Aliasghar Parvizi

Polymer Quantization Schemes for Gravitational Waves: From theory to observation

Motivated by loop quantum gravity, we propose two polymer quantization schemes to describe the propagation of gravitational waves within a classical Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime. These novel schemes yield modified waveforms, altering the amplitude of the waves as they traverse quantum spacetime. Additionally, the speed of the waves becomes frequency-dependent due to polymer corrections. We investigate the detectability of these signals using instruments like LISA and LIGO, establishing bounds on the polymer scales.

Jaroslaw Pawlowski (WUST)

Machine learning-aided quantum tomography

Alexander Ayriyan

Bayesian analysis of the equation of state of dense nuclear matter

Armen Sedrakian

Searching for the neutron star equation of state

Relativistic density functionals based on baryon-meson Lagrangians can be used to describe effectively dense matter in compact stars including hyperonic and Delta-resonance degrees of freedom. These can be supplemented with a first-order phase transition to quark matter at high densities to describe hybrid compact stars. I will discuss how the mass-radius and tidal deformability inferences from electromagnetic and gravitational wave observations constrain the current models of hypernuclear and hybrid stars. I will briefly review recent results on the bulk viscosity of dense nucleonic matter in hot compact stars, which emerged in recent years as the leading dissipative channel in binary-neutron star merger simulations.

Stefan Leupold (Uppsala, Sweden)

Exploring matter at the femtometer scale: Model-independent calculations of electromagnetic form factors

At high energies, the (transition) form factors of hadrons are most sensitive to the respective minimal quark content. At low energies, however, the form factors are dominated by universal features related to pion physics. Only these Goldstone bosons can carry information over large distances. Dispersion theory is used to obtain a model-independent representation of vector-isovector baryon (transition) form factors at low energies. The ingredients are pion-baryon scattering amplitudes and the well-measured pion vector form factor. The latter is related to the p-wave pion phase shift, which contains as its most prominent feature the information about the rho meson. As a consequence, the dispersive framework leads to a model-independent version of vector-meson dominance. In the present scheme, motivated by chiral perturbation theory, the pion-baryon amplitudes are constructed from baryon-exchange diagrams providing the long-range aspects and subtraction constants for the short-distance physics. Also here the measured p-wave pion phase shift is utilized to account for the strong interactions between the pions. The baryon exchange diagrams are typically not included in models of vector-meson dominance and also not in quark models, in clear distinction to the scheme presented here. Up to now, the subtraction constants constitute free parameters and are determined by fits to experimental or lattice data. We apply this dispersive low-energy scheme to 1. the form factors of the nucleon, with focus on the dependence on both the virtuality and the quark mass [1,2]; 2. the transition form factors of nucleon to Delta(1232) [3]; 3. the transition form factors of nucleon to N*(1520) [4]. An outlook is provided about extensions and applications to meson form factors relevant for the magnetic moment of the muon, weak form factor relevant for neutrino-matter scattering, and hadronic input for electromagnetic radiation from hot/dense strongly interacting matter.

[1] Stefan Leupold, Eur.Phys.J.A 54 (2018) 1, 1
[2] Fernando Alvarado, Di An, Luis Alvarez-Ruso, Stefan Leupold, Phys.Rev.D 108 (2023) 11, 114021
[3] Moh Moh Aung, Stefan Leupold, Elisabetta Perotti, Yupeng Yan, arXiv 2401.17756 [hep-ph]
[4] Di An, Stefan Leupold, in preparation

Marcus Sperling (Vienna)

Symplectic Singularities in Physics: Their Origins and Significance

Symplectic singularities, also known as hyper-Kahler singularities, encompass well-known geometric spaces such as the Kleinian surface singularities or the moduli space of instantons. Recently, a new class of symplectic singularities has emerged through the construction based on a physics model known as the 3d N=4 Coulomb branch. In this presentation, I aim to provide an introduction and overview of symplectic singularities in general, with a particular focus on the 3d N=4 Coulomb branches. I will place special emphasis on the symplectic singularities that manifest as moduli spaces of vacua within supersymmetric field theories containing 8 supercharges in space-time dimensions ranging from 3 to 6. These instances showcase how geometric features offer elegant descriptions of strongly coupled phenomena.

Falk Hassler

A geometric perspective on duality symmetries in supergravity

Symmetries are one of the major tools to understand the structure of physical theories. But even the most powerful symmetry is useless if it is hidden and therefore not accessible in calculations. Prominent examples are S-, T- and U-dualities of superstrings and branes. We know that they unify the five perturbative superstring theories and M-theory into a single framework, but their imprints on the low-energy effective supergravity theories are subtle and easy to miss. A framework which addresses this issue is (exceptional) generalized geometry. Although thought as a natural extension of geometry to an extended tangent bundle, it still lacks fundamental objects of differential geometry like a Riemann tensor. After a short review of the most important differences between generalized and standard differential geometry, I will present the underlying cause for this trouble and present a proposal for a solution which gives a new, geometric perspective on duality symmetries in supergravity. This approach will not just resolve some old puzzles but it also has direct applications, leading to a much broader notion of dualities in supergravity that can be used to generate new solutions using a tool known as consistent truncations.

Presentation (pdf)

David Blaschke

Isolated and eccentric millisecond pulsars from strong phase transitions in binary neutron stars

Millisecond pulsars have proven to be exceptional laboratories, serving as precise cosmic clocks and providing unique insights into stellar evolution. Their significance extends to testing theories of general relativity and probing the fundamental properties of dense matter. A unique category of millisecond pulsars is found within binary systems with a low-mass white dwarf companion exhibiting substantial eccentricity, deviating from the expected circular nature of their orbits. Exploring the mechanisms driving eccentricity in these systems provides crucial insights into the broader understanding of the inherent uncertainties associated with such complex astrophysical systems. We report results of a comprehensive analysis to investigate whether gravitational mass defects, caused by a rapid first-order phase transition from ordinary baryonic to quark matter, either with or without additional asymmetric kicks, can explain the observed eccentricity in millisecond pulsars within binary systems and also the fraction of gravitationally unbound systems, the isolated millisecond pulsars.

Presentation (pdf)

Domenico Frattulillo, Federico II University in Naples

Quantum Euler angles and agency-dependent spacetime

Quantum gravity is expected to introduce quantum aspects into the description of reference frames. Here we set the stage for exploring how quantum gravity induced deformations of classical symmetries could modify the transformation laws among reference frames in an effective regime. We invoke the quantum group SUq(2) as a description of deformed spatial rotations and interpret states of a representation of its algebra as describing the relative orientation between two reference frames. This leads to a quantization of one of the Euler angles and to the new paradigm of agency dependence: space is reconstructed as a collection of fuzzy points, exclusive to each agent, which depends on their choice of reference frame. Each agent can choose only one direction in which points can be sharp, while points in all other directions become fuzzy in a way that depends on this choice. Two agents making different choices will thus observe the same points with different degrees of fuzziness.

Ivan Pidhurskyi (CERN)

Present and future of the open charm program of the NA61/SHINE experiment

NA61/SHINE is a fixed-target particle physics experiment at CERN SPS. The experiment studies the hadronic final states produced in interactions of various target-projectile systems ranging from p+p and up to Pb+Pb at up to the top SPS energies of 150A GeV/c. One of the primary objectives of the experiment as of today is to perform a direct measurement of the open charm hadrons in the Pb+Pb collisions. Predictions from theoretical models give us estimates on the c-cbar pair yields of around 0.1-1 pair per event (Pb+Pb @ 150A GeV/c). Our previous attempts at direct measurement did not succeed. Thus, during the CERN Long Shutdown 2 the experiment was upgraded and now provides significantly better performance for our new attempt at the open charm measurements. The amount of data collected so far already exceeds the statistics used for the previous attempt by two orders of magnitude. Combining high acceptance of a fixed-target experiment, a large variety of colliding systems, and a unique energy range, the NA61/SHINE experiment provides unique opportunities for studies of the medium of deconfined matter. So far, these qualities of the experiment have been used to perform a 2-dimensional scan for the critical point of strongly interacting matter. After the aforementioned upgrades, the experiment has the potential to also become a work site for the exploration of a deconfined medium via studies of heavy quark correlations. Our latest idea is to quantify the transport properties of the strongly interacting medium via a study of the momentum correlations between the final-state open charm hadrons. Within our setup, the head-on Pb+Pb collisions would rarely produce more than one pair of the c-cbar quarks, allowing one to discard collective effects. The low energy of the collision should also result in c and cbar quarks being created essentially at rest in the center of mass frame, allowing one to avoid trivial inputs to the signal such as back-to-back momentum correlations between the quarks created in a pair.

Dmitry Zhuridov

Geometrical optics for a new window to the Universe

The breakdown of rotational invariance of an optical system is considered as a prospective way for expanding its capabilities. A new theory of aberrations for cylindrically symmetric optical systems is presented. Possible applications for telescopic systems are discussed.

Presentation (pdf)

Michael Buballa, Technical University Darmstadt

Towards a stability analysis of inhomogeneous phases in QCD

QCD inspired models, like the Nambu--Jona-Lasinio (NJL) model, suggest that the phase diagram of strong-interaction matter at moderate densities could contain regions, where the chiral condensate varies in space. A powerful method to identify these inhomogeneous phases is a stability analysis, in which the stability of the energetically preferred homogeneous state against small inhomogeneous fluctuations is investigated. Recent systematic studies of this kind have led to the suspicion that the inhomogeneous phases could be cutoff artifacts related to the nonrenormalizablity of these models. This calls for a clarification of this issue directly within QCD. In my talk I discuss a new approach for a stability analysis that is based on the two-particle irreducible effective action and compatible with full QCD calculations within the framework of Dyson-Schwinger equations. When applying this method to the NJL model we recover the result of the conventional stability analysis. For QCD the analysis is more difficult due to the nonlocality of the quark selfenergy. Preliminary results within a simple truncation will be presented.

Presentation (pdf)

Marek Szczepańczyk, University of Warsaw

The quest to detect (exceptional) gravitational-wave sources

Multi-messenger Gravitational-Wave Astrophysics is an exciting venue for discovery. The gravitational-wave observations by LIGO/Virgo/KAGRA challenge our understanding of the Universe. In particular, the discovery of gravitational waves from exceptional astrophysical sources plays a key role in this endeavor of exploring the Universe. I will explain the model-independent searches that are suitable for making discoveries. I will describe the status of the ongoing fourth observing run that started around half a year ago. Finally, I will talk about the prospects and the searches for gravitational waves from core-collapse supernova.

Martin Urbanec (Silesian University Opava, CZ)

Measuring mass and radius of neutron star using high-frequency quasi-periodic oscillations

High-frequency quasi-periodic oscillations are peaks detected in power spectra of several low-mass X-ray binaries. In this talk, I will discuss recent progress in understanding the origin of these peaks and how can we use them to measure the mass and radius of neutron star members of these binaries. Particular attention will be devoted to source 4U 1608-52 where other measurements of mass and radius are possible using X-ray bursts.

Michele Arzano, University of Naples

Entanglement entropy and horizon temperature in conformal quantum mechanics

The generators of radial conformal symmetries in Minkowski space-time can be put in correspondence with generators of time evolution in conformal quantum mechanics. Within this correspondence I show that in conformal quantum mechanics the state corresponding to the inertial vacuum for a conformally invariant field in Minkowski spacetime has the structure of a thermofield double. The latter is built from a bipartite "vacuum state” corresponding to the ground state of the generators of hyperbolic time evolution. These can evolve states only within a portion of the time domain. When such generators correspond to conformal Killing vectors mapping a causal diamond in itself and generators of dilations, the temperature of the thermofield double reproduces, respectively, the diamond temperature and the Milne temperature found for massless fields in Minkowski spacetime. We calculate the entanglement entropy associated to the thermofield double states and obtain a UV divergent logarithmic behaviour analogous to known results in two-dimensional conformal field theory in which the entangling boundary is point-like.

Presentation (pdf)

Zbigniew Haba

Is the quantum Universe Euclidean?

I review various ways to make field theory Euclidean: as a technical tool or as a dynamical outcome. Then, the problem with the Big Bang in quantum field theory will be discussed. Gibbons-Hartle-Hawking suggestion of a passage at the Big Bang from the Lorentzian signature to the Euclidean one will be explained. A simple model how this can happen will be presented. The theoretical virtues of an Euclidean origin of the universe will be advocated.

Eric Lescano

On the non-vanishing viscosity of the stringy fluids

In this talk, I will discuss about string cosmology. I will pedagogically introduce the Einstein equation in the context of string theory and I will explain what kind of fluids are effectively reproduced by the string dynamics.

James Lattimer (SUNY Stony Brook)

Neutron Stars as Windows into Dense Matter Physics

Neutron stars embody matter at extremes: they contain matter at the highest possible densities since the Big Bang, they have the highest known magnetic fields and contain the highest temperature superfluids. They are known to spin with frequencies up to 716 Hz with equatorial surface velocities approximately 1/4 of light speed, and are also known to travel through space with velocities up to 1% of light speed. General relativity predicts that neutron stars have maximum masses no greater than 3 M, radii no smaller than 8 km, and central energy densities no larger than 11 times the normal nuclear saturation density (2.7 1014 g/cm3. Recent advances in astrophysical observations, nuclear experiments and nuclear theory considerably constrain their matter properties although it is still not known if they contain deconfined quark matter. Among recent advances are observations from the binary neutron star merger GW170817 indicating that neutron stars have masses and radii no larger than 2.2 M and 13 km, respectively, while parity-violating electron scattering measurements of the neutron skin thickness of 208Pb at Jefferson Laboratory are consistent with neutron star radii 12±1 km. A 10-second long burst of neutrinos, observed from SN1987A, has long been thought to prove the accompanying birth of a neutron star, but its detection has been elusive. But the recent millimeter-wave detection of a warm dust blob in SN1987A's remnant provides evidence that this neutron star has finally been found. In addition, observations of rapid cooling of the 330 year-old neutron star in the Cassiopeia A supernova remnant are best fit if it contains interior superfluid neutrons and protons with critical temperatures near 109 K and 3109 K, respectively.

Presentation (pdf)

Valeriya Mykhaylova

Charm Quark Production in the Quark-Gluon Plasma

We study the production of charm quarks in hot QCD matter within the effective quasiparticle framework. The quark-gluon plasma (QGP) is composed of the quasiparticle excitations with dynamically generated masses. The latter are linked to the lattice QCD equation of state for 2+1 quark flavors through the effective temperature-dependent coupling. The evolution of the QGP is described by hydrodynamic simulations of viscous fluid in 2+1 dimensions, as well as by purely longitudinal propagation of perfect fluid. By solving the rate equation in the above scenarios, we investigate how the production of charm quarks depends on various properties of hot QCD matter.

Riccardo Borsato, University of Santiago de Compostela, Galician Institute of High Energy Physics

Deformations of 2D field theories and the light-cone gauge

Recently, there has been a lot of progress in the construction of deformations of 2-dimensional integrable field theories that do not break the original integrity. Often, the motivation is related to the realization of such integrable models in the context of the holographic duality, thus opening the possibility to obtain exact results for gauge and gravity theories and their deformations. At the same time, the study of such deformations has led to some puzzles that force us to better understand already the undeformed models. In particular, in this talk I will explain why it is important to carefully choose the light-cone gauge (necessary to fix the reparametrisation invariance on the worldsheet of the string) in order to have a workable description of the deformed models, and I will show how inequivalent light-cone gauges are related to each other.

Mahtab Gholami (Iranian National Observatory Tehran, Iran)

The Isaac Newton Telescope Monitoring Survey of Local Group Dwarf Galaxies. Variable Stars in the Nearest Starburst Dwarf Galaxy, IC 10

Stars are always attractive. They can be eclipsed, pulsated, flared, or even exploded depending on their nature. Over time, these processes lead to the brightness of stars varying and, as a result, observing these variations in brightness enables us to gain a better understanding of stars’ nature, evolution, birth, and death, as well as their physical processes. Variable stars help us to understand some of the most exciting objects in the sky: exoplanets, supernovas, pulsars, quasars, gamma-ray bursts, and even black holes. Here, we studied variable stars in the nearest starburst galaxy of the Local Group, IC 10! To identify variable stars in IC 10, we conducted an optical monitoring survey using the 2.5-m Isaac Newton Telescope (INT) with the wide-field camera (WFC) in the i-band and V-band from 2015 to 2017. We created a photometric catalog for 53,579 stars within the area of CCD4 of WFC, of which we classified more than 1000 stars as variable candidates, mostly asymptotic giant branch stars (AGBs) and red supergiants (RSGs), within the CCD4 area. By comparing our output catalog to the other catalogs (e.g., Pan-STARRS, Spitzer Space Telescope, and Hubble Space Telescope (HST)) we determined the success of our detection method. Furthermore, we used red giant branch stars to estimate the galaxy's distance. This study resenting the variable stars survey methodology and the photometric catalog, which will be available to the public through the Centre de Données Astronomiques de Strasbourg soon.

Jan Perina Jr. (Olomouc)

Two-beam light with simultaneous anticorrelations in photon-number fluctuations and sub- Poissonian statistics

Twin beams generated in spontaneous parametric down-conversion are endowed with highly nonclassical properties. Their entanglement has been exploited to test the quantum mechanics via the violation of the Bell inequalities, teleport the polarization state of a photon, demonstarate quantum and ghost imaging, develop the methods of ultra-precise quantum measurements and absolute detector calibration, etc. A very efficient method for sub-Poissonian light generation by photon-number-resolved postselection from twin beams has been suggested and experimentally demonstrated to arrive at the states with photon-number fluctuations reduced below the level of the vacuum state. Such states are, in certain sense, complementary to the phase squeezed states well known from, e.g., the detection of gravitational waves. We have developed and utilized the method of photon-number- resolved postselection from twin beams to demonstrate the generation of a new class of quantum states exhibiting anticorrelations in photon-number fluctuations and marginal sub-Poissonian statistics: Two twin beams with a shared signal beam and separated idler beams have been used together with the photon-number-resolving postselection in the signal beam to arrive at two coupled beams with anticorrelations in photon-number fluctuations. Moreover, the beams have exhibited the sub-Poissonian photon-number statistics in their marginal distributions under suitable conditions. The postselected fields with the increasing mean photon numbers have been reconstructed from the experimental photocount histograms by the maximum likelihood approach. Their nonclassical properties have been analyzed by suitable nonclassicality criteria and quantified by the corresponding nonclassicality depths. Determining the appropriate quasi-distributions of integrated intensities with negative values, the performance of different nonclassicality criteria has been judged. Properties of the postselected fields reached both by the used and ideal photon-number-resolved detectors have been mutually compared.

Ashutosh Dash (Frankfurt)

On the validity of Ohm's law in relativistic plasmas

Relativistic plasmas play a significant role in high-energy phenomena, including heavy-ion collisions, black-hole magnetospheres, relativistic jets, and the early universe. The coarse- grained framework for describing the motion of charged fluid is known as relativistic magneto-hydrodynamics (MHD). The MHD equations, which comprise the particle conservation law, the energy/momentum conservation laws, and Maxwell’s equations, must also be complemented by Ohm’s law. The usual Navier-Stokes form of Ohm's law is acausal and needs to be replaced with an evolution equation of the charge diffusion current with a finite relaxation time, which ensures causality and stability. This, in turn, leads to transient effects in the charge-diffusion current, the nature of which depends on the particular values of electrical conductivity and the charge-diffusion relaxation time. We will investigate in a simplified 1+1-dimensional setting in the context of heavy-ion collision, where matter and electromagnetic fields are assumed to be transversely homogeneous and are initially expanding according to a Björken scaling. We will see how the scale invariance is broken by the ensuing self-consistent dynamics of matter and electromagnetic fields. Implications of these findings on the recent measurement of charged particle directed flow by the STAR experiment will also be discussed.

Piotr Kalaczyński (NCBJ Warszawa)

Study of cosmic ray muons with KM3NeT

The KM3NeT experiment consists of two underwater Cherenkov neutrino telescopes, currently under construction at two different locations in the Mediterranean Sea. The KM3NeT detectors collect vast amounts of cosmic ray muon data already in their intermediate configurations. This talk describes foundational work done in the muon simulations for KM3NeT, focused on the Monte Carlo (MC) code CORSIKA, and the subsequent results. The MC simulation was used to train and validate machine learning models to perform a task of reconstruction of several observables related to the observed energy and number of muons. The reconstructed quantities were directly used in a study investigating the potential of KM3NeT detectors to observe the component of the atmospheric muon flux coming from decays of short-lived parent particles, called prompt muon flux. The complete KM3NeT detectors should be able to confirm the prompt signal within 4–6 years of operation, perhaps even sooner if the collected data is combined. Currently, the biggest limitation on sensitivity comes from the systematic uncertainties.

Ludwik Turko

Origin, development, and misunderstandings concerning internal symmetries

Internal symmetries, also called flavor symmetries, started in 30-ies of the last century, from Heisenberg's suggestion that if you could switch off the electric charge of the proton, there would be no way to distinguish between a proton and a neutron. This was the beginning of the SU(2) isospin symmetry, leading to the symmetry-based classification schemes of elementary particles – the eightfold way of SU(3) because of strangeness, through SU(4) because of charm, albeit without SU(6), leaving aside for some reason its truth and beauty. A proper understanding of the observable effects of internal symmetries is, however, not common knowledge. They are treated sometimes as a kind of nonabelian generalization of "regular" charges - Q, B, S, ... - which is not correct. Also, the very concept of internal symmetry-breaking is far from being obvious. Nevertheless, there is a simple way to catch the point. To follow this simple way, one seminar should be enough, to begin with ...

Linus Wulff, Mastaryk University, Brno

Stringy corrections to gravity from dualities

As a quantum theory of gravity, string theory predicts specific corrections to Einstein's theory. These corrections are in general difficult to compute. I will describe an approach that uses another characteristic feature of string theory - the existence of dualities - to constrain the form these corrections can take.

Shigehiro Yasui (Hiroshima University)

Exotic hadrons with charm and bottom flavors

Exotic hadrons are interesting in nuclear physics, because recently many of them have been discovered in experimental studies at accelerator facilities. They are called X, Y, Z, Pc and so on, and many of them possess charm and/or bottom flavors in their contents. They can be multiquark states which is quite different from the conventional hadrons, i.e., baryons and mesons, and their properties are considered to be intimately related to the essence of the strong interaction in the standard theory for elementary particles, i.e., the quark and gluon dynamics. As one of the interesting exotic hadrons, in this seminar, we focus on Tcc as well as the anti-D meson and nucleon interaction, and introduce their recent studies from theory and experiments.

David Blaschke

The 2023 Nobel Prize in Physics for Attosecond Physics

I shall review the Nobel Prize in Physics 2023 which was awarded to Pierre Agostini, Ferenc Krausz and Anne L’Huillier “for experimental methods that generate attosecond pulses of light for the study of electron dynamics in matter”. The three Nobel Prize laureates in physics 2023 are being recognised for their experiments, which have given humanity new tools for exploring the world of electrons inside atoms and molecules. They have demonstrated a way to create extremely short pulses of light that can be used to measure the rapid processes in which electrons move or change energy.

Sibylle Driezen (ETH Zurich)

Exploring integrable deformations

Recent years have seen an upsurge of interest in deformations of two-dimensional sigma-models which preserve classical integrability when present in the original model. This property enables powerful techniques for solving these models, even in non-trivial scenarios such as at strong coupling. This talk introduces classical integrability concepts and reviews the construction of a large family of integrable deformed sigma-models. We will focus on the crucial role played by “worldsheet dualities”, which have been naturally developed within the context of string theory. In the second part of the talk, we will explore the interest of applying integrable deformations on the so-called AdS/CFT correspondence, a duality connecting highly symmetrical string theories to gauge theories. Specifically, we will focus on the “Jordanian” subclass of integrable deformations and provide insights into ongoing research in this area.

Benjamin Wehmeyer

Galactic Chemical Evolution of rapid neutron capture elements and with short lived radioisotopes

The origin of the heaviest elements is still a matter of debate. For the rapid neutron capture process (r -process), multiple sites have been proposed, e.g., neutron star mergers and (sub- classes) of supernovae. R-process elements have been measured in a large fraction of metal- poor stars. Galactic archaeology studies show that the r-process abundances among these stars vary by over 2 orders of magnitude. On the other hand, abundances in stars with solar- like metallicity do not differ greatly. While the large scatter at low metallicities might point to a rare production site, why is there barely any scatter at solar metallicities? In this talk, I will discuss chemical evolution scenarios that provide an explanation for the observed abundance features of r-process elements in our Galaxy, especially at the lowest metallicities. Further, I will explain how adding short lived radioisotopes to the model can help to further constrain the r-process and other processes, and explain why certain short lived radioisotopes arrive conjointly on Earth, even though they were produced at different nucleosynthesis sites.

Michael Bussmann, HZDR & CASUS Görlitz, Germany

From data to understanding: The Center for Advanced Systems Understanding (CASUS)

Research is driven by data that is not yet understood. This is apparent in fundamental research. Yet, our understanding of real life phenomena opens up a new view on what it means to understand data. Today, we are facing a wealth of highly detailed, high quality scientific data from large scale research facilities, observatories, sensor arrays or satellites. At the same time, Exascale computing opens up new paths to simulate these systems including all the details we find in our observations. This introduces a new challenge, namely mastering complexity. This is already visible in the rise of Artificial Intelligence methods. Yet, we are faced with a situation where the human understanding of the interrelation of the interacting parts in a complex system require new digital methods to understand their structure and dynamics. In this talk we cover some examples on how digital methods can help to shed new light on highly complex systems and how developing these methods can foster interdisciplinary research.

Presentation (pdf)

Volker Koch (LBL Berkeley, USA)

Fluctuations and the QCD Phase diagram

We analyze the behavior of (net-)proton number cumulants in central collisions of heavy ions across a broad collision energy range by utilizing hydrodynamic simulations. The data from STAR and HADES Collaborations at lower collision energies indicate an excess of (multi-)proton correlations over the non-critical reference. This observation is discussed in the context of different mechanisms, including the possibility of a critical point in the baryon-rich region of the QCD phase diagram.

José S. Andrade Jr. (Universidade Federal do Ceara)

Localization and self-organization in flow of non-Newtonian fluids

In the first part of the talk we show through extensive numerical simulations that the flow pattern inside a “swiss-cheese” type of pore geometry can be systematically controlled through the intrinsic rheological properties of the fluid. Precisely, our analysis reveals that the velocity field in the interstitial pore space tends to display enhanced channeling under certain flow conditions. This observed flow “localization”, quantified by the spatial distribution of kinetic energy, can then be explained in terms of the strong interplay between the disordered geometry of the pore space and the nonlinear rheology of the fluid. Our results disclose the possibility that the constitutive properties of the fluid can enhance the performance of chemical reactors and chromatographic devices through control of the channeling patterns inside disordered porous media. Recent results from high-resolution microfluidic experiments supporting these observations are also shown. In the second part of the talk, we focus on the statistics of structural and physical properties of non-Newtonian turbulent systems. Precisely, we show through Direct Numerical Simulations (DNS) that the statistical properties of non-Newtonian turbulent flows at the inertial subrange, calculated in terms of vortex size distributions and structure functions, follow in general the behavior of Newtonian turbulence, regardless of the rheological properties of the fluid. This structural invariance, is achieved through a self-organized mechanism at the microscopic scale of the turbulent motion that adjusts the ratio between the viscous dissipations inside and outside the vortices. However, the deviations from the K41 theory of the structure functions’ exponents reveal that the anomalous scaling, observed for Newtonian turbulence, exhibits a systematic nonuniversal behavior with respect to the rheological properties of non-Newtonian fluids.

Aleksander Kozak

Conformally-invariant framework for scalar-tensor theories of gravity in the metric, Palatini, and hybrid approaches

In my talk, I will summarize the research I conducted as a Ph.D. student at the Institute of Theoretical Physics. I will focus on the issue of conformal frames in modified gravity theories. Modified theories of gravity (or extended theories of gravity) introduce ambiguity in the description of gravitational phenomena related to the fact that there exists a multitude of conformal frames yielding - possibly - inequivalent predictions. In the literature, the most common frames are the Einstein and Jordan frames, and the issue of which one is correct remains a topic of debate. However, it was shown recently that it would be possible to construct a conformally-invariant framework for metric scalar-tensor (ST) theories of gravity. I will demonstrate that it is possible to extend the framework of conformal invariants to the case of Palatini ST theories of gravity. The connections between different versions of ST theories will also be explored. Some remarks on choosing the ‘right’ conformal frame will also be made. In the second part of my talk, I will move on to discussing applications of the invariant framework. It will be demonstrated that, in the minisuperspace formalism applied to the cosmological scenarios, the lapse function can be treated as a conformal factor, which will enable us to simplify the considerations and find integrals of motion for different theories. We will also revisit the connections between f(R) theories in different approaches and their ST representations. In the end, the conformally-invariant Tolman-Oppenheimer-Volkoff equation will be discussed.

Zbigniew Haba, Pok Man Lo, David Blaschke

50th anniversary of the discovery of asymptotic freedom in QCD

Zbigniew Haba: Asymptotic freedom in QFT
I shall discuss first why QFT (like QED) without the asymptotic freedom is in trouble. Then, I show the virtues of theories with the asymptotic freedom: a reliable weak coupling expansion and (possibly) continuum limit of lattice gauge theories.
Presentation (pdf)

Pok Man Lo: Nonperturbative QCD in Coulomb Gauge
This talk focuses on the confinement of quarks and gluons in nonperturbative Quantum Chromodynamics (QCD) within the Coulomb gauge framework. We explore the mechanisms underlying confinement and discuss their implications for constructing low-energy effective models.
Presentation (pdf)

David Blaschke: Asymptotic freedom and confinement in neutron star matter
The proof of asymptotic freedom in QCD prompted the hypothesis that in the dense interiors of neutron stars quarks should be deconfined and they appear as “giant MIT bag”. I discuss the recent picture of linking confinement and asymptotic freedom in neutron stars.
Presentation (pdf)

Yuri Shtanov, Bogolyubov Institute for Theoretical Physics, Kiev, Ukraine

Facets of f(R) gravity: inflation, dark matter, scale symmetry breaking

We discuss several facets of the metric f(R) gravity theory coupled to the Standard Model. The theory contains an extra scalar degree of freedom (the scalaron), which can be employed in several interesting ways. Firstly, if the scalaron is very heavy, it can play the role of an inflaton. In this case, a typical f(R) theory is equivalent to scalar-field models with hilltop or tabletop potentials in the Einstein frame. Inflationary evolution in such models can proceed in two alternative directions: towards the stable point at small scalar curvature describing the observable universe, or towards the asymptotic region at large scalar curvature. A universe evolving towards this asymptotically free gravity region will either run into a "Big-Rip" singularity or inflate eternally. Secondly, the scalaron in metric f(R) gravity can be a dark-matter candidate if its mass lies in the range between around 4 meV and 1.2 MeV. The scalaron manifests itself as an almost sterile cold dark matter, and one of its possible observational verifications consists in measuring specific Yukawa gravitational forces on submillimeter spatial scales. We will discuss initial conditions for the scalaron in the early universe and the role played by the Higgs field and electroweak crossover in the formation of these initial conditions. Thirdly, the scalaron in scale-invariant R^2 gravity theory can play the role of a massless dilaton breaking the scale (and electroweak) symmetry and generating the mass scale in quantum field theory. We briefly discuss this model and its fine-tuning.

MS Teams meeting

Richard Kerner (Paris)

The end of the Universe - and what next?

The fate of our Universe has been of great concern to human beings since the dawn of civilization. We shall briefly expose various versions of birth and death of the Universe as perceived by several ancient civilizations; after that the development of a scientific approach to cosmogony and cosmology will be presented. We shall also discuss the standard model prevailing nowadays, with its strong and weak points. Numerical estimates of longevity of stars, galaxies and atoms will be given too, with some philosophical comments as concluding remarks.

Prof. Richard Kerner, Sorbonne University, Paris

Non-linear Electrodynamics derived from the Kaluza-Klein Theory

The Lagrangian of the Kaluza-Klein theory, in its simplest five-dimensional version, should include not only the scalar curvature R, but also the quadratic Gauss-Bonnet invariant. The general Lagrangian is computed and the resulting non-linear equations which generalize Maxwell's system in a quite unique way are investigated. The possibility of the existence of static solutions is presented, and the qualitative behaviour of such solutions is discussed.

Presentation (pdf)

Jorge Ovalle (Silesian University in Opava)

Regular black holes without Cauchy horizons? The role of integrable singularities

Although we cannot understand the true nature of singularities in the framework of GR, it is possible to evade them by following a fairly simple strategy: generate regular BHs by filling the spacetime around the central singularity with some physically reasonable source of matter (which could be consequence of some new gravitational sector). This has produced a plethora of new regular BH solutions in recent years, mainly because the matter source used to evade the central singularity can be interpreted in terms of nonlinear electrodynamics. However, all these regular BH solutions contain a Cauchy horizon, a null hyper-surface beyond which predictability breaks down, and also leads to mass inflation at the perturbative level, a pathology which occurs even in loop quantum gravity inspired models. Even though the strong cosmic censorship conjecture establish the impossibility of extending spacetime beyond this region, in this talk we show how far we can go, without invoking this conjecture, in the building of a physically reasonable black hole without a Cauchy hyper-surface. Following this reasoning, we find a black hole lacking of Cauchy horizon, asymptotically flat and satisfying either the strong or dominant energy condition. The above is possible by demanding integrable singularity for the Ricci scalar, whose direct consequence is the appearance of finite tidal forces.

Kajetan Niewczas

Multinucleon knock-out in neutrino-nucleus scattering: Merging theory and Monte Carlo simulations

The precise measurement of neutrino properties is among the highest priorities in fundamental particle physics, involving extensive experimental efforts worldwide. Accelerator-based neutrino experiments provide a unique framework for such studies, providing oscillation measurements and hints of the CP violation in the leptonic sector. However, since these experiments rely on the interaction of neutrinos with bound nucleons inside atomic nuclei, understanding the hadronic and nuclear physics of these interactions constitutes a challenging source of uncertainty. Modeling neutrino-nucleus scattering processes is a complex many-body problem, traditionally performed in the independent- particle picture, focusing on the quasielastic neutrino-nucleon interactions or the excitation of nucleon resonances. Improving our knowledge of such cross sections to the required percent levels involves conducting research beyond the first approximation, incorporating the effects of nucleon correlations and multinucleon knock-out processes. The presented research involves a novel, multidirectional approach to tackling these problems by combining the theoretical experiences of the Ghent group and the Monte Carlo neutrino event generator NuWro, explicitly used in experimental analyses. The nuclear physics of Ghent involves a non-relativistic, mean-field-based model for both the initial and final hadronic states. On top of that, we add dynamically generated short-range nucleon correlations and explicit two-body dynamics with meson-exchange currents involving isobar degrees of freedom. This framework, exhaustively compared against electron scattering, provides predictions of inclusive, semi-inclusive, and exclusive cross sections for neutrino- nucleus interactions leading to 1-particle-1-hole and 2-particle-2-hole final states. Together with auxiliary advancements in other aspects of Monte Carlo simulations, we will present the implementation of the obtained two-nucleon knock-out model in NuWro and compare it to experimental neutrino data, therefore completing the bridge between the theoretical and experimental sides of accelerator-based neutrino research.

Prof. Günther Hasinger

Is Dark Matter made up of Primordial Black Holes?

The cosmic X-ray background radiation has been almost completely resolved into discrete objects, mainly from the growth of massive black holes in the universe. However, a few years ago, evidence for a new population of black holes from the early universe emerged from the correlation of fluctuations in the X-ray and infrared backgrounds. Similarly, quasars have been discovered with astonishingly massive black holes already formed shortly after the Big Bang. The detection of gravitational waves from the merger of pairs of very heavy, apparently non-rotating stellar black holes presents another puzzle. Recently, using the micro-lensing effect and distance determination with the ESA satellite GAIA, about 20 black holes in our galaxy have been discovered with masses that cannot be generated by stellar processes. In the past few months, the discovery of several galaxies that formed very early in the universe with the James Webb Space Telescope has been surprising, seeming to contradict the classical understanding of cosmology. All of these phenomena can be explained by so-called primordial black holes that formed immediately after the Big Bang and may represent the previously unexplained dark matter.

Presentation (pdf)

Carlos Naya (Kraków)

Versatile 3D solitons: from the Skyrme model to frustrated magnets

In the last years, the study of topological solitons and related structures in condensed matter systems has attracted much attention. Different configurations such as planar Skyrmions or Hopfions have been studied in detail, but 3D Skyrmions, resembling those from the Skyrme model of nuclei, have remained elusive. In this talk, I will present a modification of the Skyrme model which interpolates between Hopfions and usual 3D Skyrmions. Then, I will focus on how this model can be realised in frustrated magnets, showing they can host these configurations. I will pay attention to solitons arising for different values of the topological charge and their similarities to those from the Skyrme model of nuclei.

Oleksii Ivanytskyi

Early deconfinement of asymptotically conformal color-superconducting quark matter in neutron stars

I present a relativistic density functional approach to color superconducting quark matter, which mimics quark confinement by a fast growth of the quasiparticle self-energy. It can be mapped to a chiral quark matter model with medium dependent couplings which is applied to describe the high density regime of quark matter with a special emphasis on reaching the conformal limit of QCD. While the (pseudo-) scalar, vector-isoscalar and vector-isovector sectors of the model are fitted to the mesonic mass spectrum and to the vacuum phenomenology of QCD, the coupling strength in the diquark channel is defined using the Fierz transformation argument. The remaining ambiguity of the model parameters is reduced by comparing the asymptotics of the quark matter pressure normalized to the Stefan-Boltzmann limit with the perturbative QCD result. The approach is confronted with the observational constraints from measurements of mass, radius and tidal deformability of neutron stars. These constraints favor an early onset of deconfinement and color superconductivity in neutron stars with onset masses below one solar mass. We discuss also the QCD phase diagram whereby a new two-zone interpolation scheme for the construction of the hadron-to-quark matter transition is developed. The formation of color-superconducting quark matter is shown to drive the trajectories of its evolution in supernovae and neutron star mergers towards the regimes of temperature and density reached in terrestrial experiments with relativistic heavy-ion collisions.

Presentation (pdf)

Piotr Brzeski

Percolation of hyperspheres in dimensions 3 to 5

In my talk I will present a method of studying the onset of percolation of overlapping discrete hyperspheres on hypercubic lattices in dimension D = 3, 4, 5. Taking the continuum limit of the thresholds for discrete hyperspheres we obtain the values of percolation thresholds for continuous hyperspheres. In D = 3 we improved the value of the correlation length exponent. In D = 4 and 5 we obtained the continuous percolation thresholds of hyperspheres with much better quality than previously known.

Jerzy Kowalski-Glikman

Why there is (almost) nothing rater than something? The cosmological constant problem

In the talk, I will present a new understanding of the cosmological constant problem, built upon the realization that the vacuum energy density can be expressed in terms of a phase space volume. To this end, a UV-IR regularization is introduced, which implies a relationship between the vacuum energy and entropy. Combining this insight with the holographic bound on entropy then yields a bound on the cosmological constant consistent with observations. It follows that the universe is large, and the cosmological constant is naturally small, because the universe is filled with a large number of degrees of freedom.

Gerd Röpke (University of Rostock & IFT)

Clusters and few-body correlations in hot and dense nuclear matter

A Green's function approach is used to investigate correlations and cluster formation of nucleons in nuclear matter at temperatures up to 100 MeV. This thermodynamic Green's function approach is applied to hadronic matter at subsaturation densities where light nuclei as well as continuum correlations determine the thermodynamic and transport properties, in particular phase transitions and neutrino transport. The quantum statistical approach is also applied to hadronization phenomena in the quark-gluon plasma, which occur at higher densities and temperatures. Clusters are described as quasiparticles, medium modifications owing to self-energy terms and Pauli-blocking effects are calculated. In particular, the role of unstable nuclei is investigated. The treatment of correlations and cluster formation is of interest to astrophysics, for example, the structure and temporal evolution of neutron stars. In laboratory experiments, properties of matter at extreme energy densities are investigated with heavy-ion collisions, e.g., at LHC. Medium modifications as well as nonequilibrium approaches are applied to explain the observed yields of light clusters.

Presentation (pdf)

Kamil Skwarczyński

Constraining neutrino cross-section and flux models using T2K Near Detector with proton information in Markov chain Monte Carlo framework

T2K is a long-baseline neutrino oscillation experiment, which studies the oscillations of neutrinos from a beam produced using the J-PARC accelerator chain. The neutrino beam propagates over 295 km before reaching the Super-Kamiokande detector, where they can be detected after having oscillated. The ability of the experiment to run with either neutrino beams or anti-neutrino beam makes it well suited to study the differences between the oscillations of neutrinos, in particular to look for a possible violation of CP symmetry in the lepton sector. T2K has produced a new analysis of its first 10 years of data, with improved models to describe neutrino interactions and fluxes as well as additional samples of near and far detector events. We will present the results of the measurement of the parameters describing neutrino oscillations obtained with the new analysis.

Tomasz Trześniewski

Gravity - classical, quantum and phenomenology, in the context of the 59th Karpacz Winter School in Theoretical Physics

The 59th Winter School of Theoretical Physics (12th-21st February this year) was organized by our Institute together with a COST Action CA 18108 "Quantum gravity phenomenology in the multi-messenger approach", for which it was the Third Training School. The subject matter of the School touched upon different areas of research framed by the title "Gravity - Classical, Quantum and Phenomenology". Namely, the six lecture series were devoted to: asymptotic symmetries of the gravitational field (at the so-called corners), the perturbative framework for gravitational waves emitted by black holes, the theoretical grounds and practical methods of observational cosmology, models of modified gravity and bounds imposed on them by observations, the status and prospects of phenomenology of quantum gravity, and analysis of the gamma-ray telescopes data in the context of Lorentz invariance violation. The investigations of topics discussed in the lectures, and many others related to them, are motivated in particular by the search for signatures (i.e. phenomenology) of Planck-scale physics in the observations of various cosmic messengers, i.e. (ultra-high-energy) cosmic rays, astrophysical neutrinos, gamma-ray bursts and gravitational waves. This approach to the problem of quantization of gravity has recently been summarized in an extensive review published by the COST Action.

Presentation (pdf)

Michał Tomczak (IA)

’De revolutionibus’ narratio secunda

The 550th anniversary of Mikołaj Kopernik's birth is a perfect opportunity to recall his opus magnum "De revolutionibus". In my talk I will present basic motivations of Kopernik which brought him to announce a new model of the Universe called nowadays: Copernican heliocentrism. I will describe also a long story of completing of "De revolutionibus". I will show that the discovery of Kopernik might be even more advanced than usually thought - his book contains all values needed to formulate the 3rd Kepler law! I will illustrate my talk by citations from "De revolutionibus".

Presentation (pdf)

David Osten

Duality as a symmetry principle for sigma models

Sigma models are a big class of theories, omnipresent in many branches of physics -- from condensed matter over particle physics to gravity and string theory. In this talk I want to motivate how a mathematical tool from string theory, duality and so-called generalized geometry, can be used to approach and get new insights into general sigma models. In particular, I will emphasize the role that generalized geometry plays for topological sigma models, integrable sigma models and those with non-commutative field spaces.

Presentation (pdf)

Artur Ankowski

Determination of the argon and titanium spectral functions from (e, e'p) data

Reliable reconstruction of neutrino energy in the Deep Underground Neutrino Experiment and in the Fermilab-based short-baseline oscillation program requires a realistic description of the ground state properties of the argon nucleus. Toward this goal, the E12-14-012 experiment in Jefferson Lab Hall A measured proton knockout from argon and titanium (the mirror nucleus of argon) induced by scattering of 2.2-GeV electrons, collecting data over a broad range of the initial proton's momenta and the excitation energies of the residual nucleus. Presenting the results of the recent papers, L. Jiang et al. PRD 105, 112002 (2022) and PRD 107, 012005 (2023), I will describe the analysis that led to the extraction of the proton spectral functions of argon. I also will discuss the obtained results in the context of past proton-knockout experiments.

Presentation (pdf)

Ludwik Turko

Altered Probability States

The outcomes of a given measurement of any scientific observables can be considered random variables. The crucial point is to find and apply statistical methods that enable a reasonable inference of measured observables and scientific models used to describe phenomena of interest. The statistical inference, however, is contingent on the notion of probability and how this notion is applied to the description and characterization of experimental results. Altered Probability States then appear, based on two different interpretations of the notion of probability: frequentist interpretation based on the set theory and subjective, called also Bayesian, interpretations based on extensions of logic. The seminar will be devoted to the comparison of both approaches, their inference methods, and ranges of applicability. Real-life examples will be presented.

Presentation (pdf)

Gregor Kosec (Jožef Stefan Institute Ljubljana)

Adaptive meshfree approach to solving partial differential equations

Many natural and technological phenomena are modelled through Partial Differential Equations (PDEs), which can rarely be solved analytically - either because of geometric complexity or because of the complexity of the model at hand. Instead, realistic simulations are performed numerically. There are well-developed numerical methods that can be implemented in a more or less effective numerical solution procedure and executed on modern computers to perform virtual experiments or simulate the evolution of various natural or technological phenomena.
The key element of any numerical method for the solution of partial differential equations (PDE) is discretization of the domain. In traditional numerical methods such as the finite element method (FEM), this discretization is typically performed by partitioning the domain into a mesh, i.e., a finite number of elements that entirely covers it. Despite substantial developments in the field of mesh generation, the process of meshing often remains the most time-consuming part of the whole solution procedure while the mesh quality limits the accuracy and stability of the numerical solution.
In response to the tedious meshing of realistic 3D domains, required by FEM, and the geometric limitations of FDM and FVM, a new class of mesh-free methods emerged in the 1970s. The conceptual difference between mesh-based and mesh-free methods lies in the consideration of relationships between the computational nodes. Mesh-free methods, as their name implies, fully define the relationship between nodes only by the internodal distances and thus free themselves from the shackles of using mesh. An important implication of this simplification is that mesh-free methods can operate on a set of scattered nodes. Although it is generally accepted that certain rules must be followed when generating such scattered nodes, the positioning of nodes is significantly less complex compared to meshing and can be automated regardless of the dimensionality or shape of the domain under consideration.
In this seminar we will discuss core elements of adaptive mesh-free numerical analysis, e.g. quasi-uniform and variable density node generation including consideration of problems on domains whose boundaries are represented as computer-aided design (CAD) models, high order differential operator approximation, and adaptive solution procedure. The discussion will be supported with examples ranging from simple solution of Poisson equation to the coupled system of non-linear PDEs describing thermo-fluid dynamics in irregular 3D domain.

Amir Khan, Max Planck Institute, Heidelberg, Germany

General Neutrino Interactions and its Phenomenology

In this talk, I will give an overview of the general neutrino interactions, namely, vector (V), axial-vector (A), scalar (S), pseudoscalar (P), and tensor interactions (T) and their origins. I will discuss the phenomenology of the general neutrino interactions and their importance in the neutrino oscillation and absolute mass experiments, direct detection dark matter experiments and some early universe measurements. I will report recent experimental limits from different experiments. I will also briefly discuss connections between the general neutrino interactions with some simplified models.

Teams link
Zoom link part 1
Zoom link part 2

Mateusz Cierniak

Multi-quark clusters and their Mott dissociation in hot, dense matter

We describe multiquark clusters in quark matter within a Beth-Uhlenbeck approach in a background gluon field that is coupled to the underlying chiral quark dynamics using the Polyakov-gauge and an effective potential for the traced Polyakov-loop. A higher multiquark cluster of size n is described as a binary composite of smaller subclusters n_1 and n_2 (n_1+n_2=n) with a bound state and scattering state spectrum. For the corresponding cluster-cluster phase shifts we use two simple ansätze that capture the Mott dissociation of clusters as a function of temperature and chemical potential. We compare the simple "step-up-step-down" model that ignores continuum correlations with an improved model contains them in a generic form. In order to explain the model, we restrict ourselves here to the cases where n= 1, 2, ..., 6. A striking result is the suppression of the abundance of colored multiquark clusters at low temperatures by the coupling to the Polyakov loop. This is understood in close analogy to the suppression of quark distributions by the same mechanism and we derive here the corresponding Polyakov-loop generalized distribution functions of n-quark clusters.

Presentation (pdf)

Michele Arzano

Getting hot without accelerating: diamond and Milne temperature from conformal quantum mechanics

The generators of radial conformal symmetries in Minkowski space-time can be put in correspondence with the generators of time evolution in conformal quantum mechanics. Within this correspondence I show that in conformal quantum mechanics the state corresponding to the inertial vacuum for a conformally invariant field in Minkowski spacetime has the structure of a thermofield double. The latter is built from a bipartite "vacuum state” corresponding to the ground state of the generators of hyperbolic time evolution. These can evolve states only within a portion of the time domain. When such generators correspond to conformal Killing vectors mapping a causal diamond in itself and generators of dilations, the temperature of the thermofield double reproduces, respectively, the diamond temperature and the Milne temperature. This result indicates that, for conformally invariant fields, the fundamental ingredient at the basis vacuum thermal effects in flat-space time is the non-eternal nature of the lifetime of observers rather than their acceleration.

dr David Osten

New classically integrable sigma models based on Z(N)-symmetric homogeneous spaces

Typical two dimensional integrable sigma models are those which have group manifolds or Riemannian symmetric spaces, or in other words homogeneous spaces with a Z(2)-grading, as target spaces. This construction can be generalised to homogeneous spaces based on a Z(N)-grading. After a review of these sigma models and their classical integrability, I present new types of sigma models with Z(N)-symmetric homogeneous target spaces and some of their deformations. I comment on the geometric interpretation of the Z(N)-symmetry, the applicability as string sigma models and Hamiltonian integrability

Alessandro Drago (INFN and University Ferrara)

Strange white dwarfs

More than 20 years ago, Glendenning et al. (1995) proposed the existence of stable white dwarfs with a core of strange quark matter. More recently, by studying radial modes, Alford et al. (2017) concluded that those objects are unstable. We investigate again the stability of these objects by looking at their radial oscillations, and we assume that there is no phase transition between hadronic and quark matter at the strange core interface, following the formalism developed by Pereira et al. (2018) and Di Clemente et al. (2020). Our analysis shows that if the star is not strongly perturbed and ordinary matter cannot transform into strange quark matter, this type of objects are indeed stable. On the other hand, ordinary matter can be transformed into strange quark matter if the star undergoes a violent process, as in the early stages of a supernova, causing the system to become unstable (as described by Alford et al. (2017)) and collapse into a strange quark star. In this way, km-sized objects with subsolar masses can be produced.
Di Clemente, Drago, Pagliara and Char, arXiv:2207.08704 [astro-ph.SR]
Glendenning, Kettner, Weber, PRL 74 (1995) 3519; ApJ 450 (1995) 253
Alford, Harris, Sachdeva, ApJ 847 (2017) 109
Pereira, Flores, Lugones, ApJ 860 (2018) 12
Di Clemente, Mannarelli, Tonelli, PRD 101 (2020) 103003

Presentation (pdf)

Attila Cangi (CASUS/HZDR)

Physics-informed neural network models for predicting the electronic structure of matter

Artificial intelligence (AI) has great potential for accelerating electronic structure calculations to hitherto unattainable scales [1]. I will present our recent efforts accomplishing speeding up Kohn-Sham density functional theory calculations at finite temperatures with deep neural networks in terms of our Materials Learning Algorithms framework [2,3] by illustrating results for metals across their melting point. Furthermore, our results towards automated machine learning save orders of magnitude in computational efforts for finding suitable neural networks and set the stage for large-scale AI-driven investigations [4]. Finally, I will conclude with a preview of our most recent result that enables neural-network-driven electronic structure calculations for systems containing more than 100,000 atoms.
[1] L. Fiedler, K. Shah, M. Bussmann, A. Cangi, Phys. Rev. Materials 6, 040301, (2022).
[2] A. Cangi, J. A. Ellis, L. Fiedler, D. Kotik, N. A. Modine, V. Oles, G. A. Popoola, S. Rajamanickam, S. Schmerler, J. A. Stephens, A. P. Thompson, MALA, https://doi.org/10.5281/zenodo.5557254 (2021).
[3] J. A. Ellis, L. Fiedler, G. A. Popoola, N. A. Modine, J. A. Stephens, A. P. Thompson, A. Cangi, Phys. Rev. B 104, 035120 (2021).
[4] L. Fiedler, N. Hoffmann, P. Mohammed, G. A. Popoola, T. Yovell, V. Oles, J. A. Ellis, S. Rajamanickam, A. Cangi, Mach. Learn.: Sci. Technol. 3 045008 (2022).

Presentation (pdf)

Nazarii Sudak

Framework for constructing Wigner functions of an arbitrary quantum systems

A possibility of constructing a Wigner function for any quantum state has been a subject of investigation for over 50 years. A datailed discussian of a general and consistent framework for constructing a Wigner function which fully describe any quantum system of arbitrary dimension or ensembele size will be presented.

Piotr Kopszak

Port based teleportation - the protocol, it's performance and the degradation of the resource

In my talk I will describe so-called port-based teleportation (PBT) protocol, i.e. a teleportation protocol that, unlike the standard teleportation introduced by Bennet et al. in 1993, does not require the unitary correction in the last step. It does so at the cost of limited teleportation efficiency. I will describe the qualitative analysis of the protocol which were possible to obtain thanks to the system's symmetryies with respect to partially transposed permuitation operators. In the second part I will concentrate on the more specific task of estimation of the degradation that the resource state undergoes in one round of PBT and it's usefulness for the purther teleportations (so called entanglement recycling).

Armen Sedrakian

Recent developments in the understanding of the M-R diagram of compact stars with first-order phase transition

After a short introduction and review of the structure of compact stars with phase transition to QCD phases, I will present some selected results that have been obtained in 2022. In particular, I will discuss the new findings about ultra-compact hybrid stars and the issue of stability of hybrid stars when the conversion between the two phases is slow at the transition interface.

Dr. Amir Khan, Max Planck Institute, Heidelberg, Germany

General Neutrino Interactions and its Phenomenology

In this talk, I will give an overview of the general neutrino interactions, namely, vector (V), axial-vector (A), scalar (S), pseudoscalar (P), and tensor interactions (T) and their origins. I will discuss the phenomenology of the general neutrino interactions and their importance in the neutrino oscillation and absolute mass experiments, direct detection dark matter experiments and some early universe measurements. I will report recent experimental limits from different experiments. I will also briefly discuss connections between the general neutrino interactions with some simplified models.

link to the meeting

Dmitry Zhuridov

Neutrinos in Heaven and on Earth: from Baryogenesis to Monte Carlo Generation

Personal achievements of the speaker in the neutrino physics since Ph.D. defence will be outlined. In this retrospective, neutrinos are considered as an invisible bridge connecting cosmological theories and particle physics experiments. First, cosmological aspects of neutrinos such as the baryogenesis and the dark matter in the universe with their relation to the involved neutrino properties will be discussed. Then several tests aimed to improve our knowledge of the known neutrino properties and discover the new ones will be reviewed, in particular, experiments on high-energy particle collisions, rare decays of nuclei, neutrino oscillations, etc. A particular role of the Monte Carlo generation that connects neutrino theory to experiment will be pointed out.

Artur Ankowski

Path to accurate neutrino cross sections

To shed light on the difference between matter and antimatter in the Universe, the Deep Underground Neutrino Experiment (DUNE) and Hyper-Kamiokande will analyze the oscillations of neutrinos and antineutrinos with unprecedented precision. The success of these challenging studies requires a substantial improvement of our understanding of neutrino interactions with atomic nuclei over the next decade. Dedicated studies performed in the MINERvA experiment show that the simulations currently available are woefully inadequate to meet the needs of the oscillation program. This issue can lead to a sizable bias in the extracted oscillation parameters. In this talk, I will present DUNE and Hyper-K in the broad context of rapidly progressing neutrino physics, and explain why it is difficult to pinpoint the origin of the discrepancy between the model and data based on neutrino data alone. I will argue that electron-nucleus and neutrino-nucleus interactions share a lot of common physics, but electron scattering offers a fundamental advantage of precisely known kinematics of interaction, in addition to much higher cross sections. Discussing a recent article [PRD 102, 053001 (2020), arxiv:2006.11944], I will present the most extensive comparison to date of the cross sections from GENIE, the Monte Carlo generator most commonly used in neutrino physics, against electron-scattering data, exploring the kinematics of DUNE and Hyper-K. I will discuss a number of problems that need to be resolved, show to what extent other generators employed in neutrino physics also suffer from these issues, and offer directions for possible improvements.

Vivek Thapa (Indian Institute of Technology Jodhpur)

Investigation of exotic particle spectrum in cold compact stars

Astrophysical observations provide the sole signature of high dense matter in the compact stars. Due to the restrictions in our terrestrial laboratories and hence insufficient experimental knowledge about the matter properties at density regimes higher than saturation density, it is very difficult and challenging to predict dense matter behavior. Hence, in order to do so, the modelling of dense matter equation of states, constructing the compact star structures and followed by constraining with the different astrophysical observations are inevitable. There are several compact star observable properties (mass-radius configurations, gravitational-wave signatures) which are directly or indirectly related to specific composition, phase and dense matter attributes. We investigated the possibility of (anti)kaon condensation and its subsequent effects on the properties of compact stars that develop hypernuclear cores with and without an admixture of $\Delta$-resonances working within the framework of relativistic mean-field model which enriched the conceptual understanding of cold dense matter inside these compact stars.

Michał Bobula

Rainbow Oppenheimer-Snyder collapse and the entanglement entropy production

I derive a new model of black-to-white hole transition - the classical Oppenheimer-Snyder dust ball interior is modified with Loop Quantum Cosmology dynamics. I consider the rainbow metric approach for both pure dust ball collapse and the similar scenario accounting for scalar field perturbations. The collapsing matter bounces and reemerges in a new universe. Exterior geometry is extracted as well as the global causal structure of the process. I study entanglement entropy production to verify whether the black hole information paradox exists within the model.

Hélder Larraguível (Uniwersytet Warszawski)

Who put a knot in my 3d N = 2 supersymmetric gauge theory?

At first sight no one would imagine that computing the index of the 3d N = 2 SUSY theory would yield knot invariants, but surprisingly it does! Not only that, the 3d index allowed us to obtain explicit expressions for several knot invariants arising from Chern-Simons theory, which were unknown before! How could that be? First discovered in topological string theory, the duality between 3d Chern-Simons theory and 3d N = 2 SUSY has even introduced new knot invariants, with physical interpretation of BPS particles, or open Gromov-Witten invariants. Given the central role of this duality, I will initially discuss the opposite direction, what other knot invariants teach us about 3d N = 2 SUSY. Then, I will present the results of ongoing effort with my collaborators towards understanding why many distinct 3d N = 2 SUSY theories have the same knot, and how many are they.

Eric Lescano, Ruđer Bošković Institut (Zagreb, Croatia)

Statistical matter coupled to the (double) geometry

This talk will be about cosmology and string theory and it will have two parts. In the first one we will review the inclusion of statistical matter in Riemannian geometries. Our starting point will be the Einstein equation and we will focus on energy-momentum tensors that depend on hydrodynamics/thermodynamics variables, such as the perfect fluid. We will derive conservation laws considering relativistic kinetic theory. We will finish this part with a quick introduction to the low energy limit of string theory (supergravity) and its Double Field Theory (DFT) rewriting. In the second part of the talk we will include statistical matter in DFT (based on 2003.09588), we will construct the energy-momentum tensor for the perfect fluid in the double geometry (based on 2111.03682) and finally we will discuss about the relation between string cosmologies, DFT cosmologies and alpha'-corrections (based on 2207.04041).

Nazarii Sudak

Phase space description of quantum optics

A classical particle has a definite position and momentum and is therefore represented as a point in phase space. When there is a set of particles, the probability of finding a particle in a certain small volume of phase space is given by the probability distribution function. This is not true for a quantum particle due to the uncertainty principle. Instead, one can introduce a quasi-probability distribution, which is not required to satisfy all the properties of a normal probability distribution function. For example, the Wigner function becomes negative for states that have no classical counterparts, so it can be used to identify non-classical states. Connection to other quasiprobability functions such as Glauber's-Sudarashan P function and Husimi Q function will also be shown.

Artur Barasiński

2022 Nobel Prize in Physics for Quantum Information Experiments

The Nobel Prize in Physics 2022 was awarded jointly to Alain Aspect, John F. Clauser and Anton Zeilinger "for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science". In the talk, I will briefly explain the groundbreaking experiments using entangled quantum states. In particular, I will discuss Bell’s theorem which demonstrates the quantum nature of the microworld and the existence of quantum entangled states describing composed systems. Such states are, for instance, the basis of the quantum teleportation protocol, which allows the transfer of complete information about the quantum state under study while transmitting only classical information in the form of a short sequence of bits.

Chihiro Sasaki

A new WPI research center at Hiroshima University - prospects and missions

The Japan Society for the Promotion of Science has announced on Oct 13 that Hiroshima University was selected to host a new research center funded by the Ministry of Education, Culture, Sports, Science and Technology within the framework, called WPI (The World Premier International Research Center Initiative). The new center, International Institute for Sustainability with Knotted Chiral Meta Matter, will introduce the paradigm to cross- pollinate the knowledge of chirality and topology across disciplines and scales. I will present a brief overview of the WPI center's missions and prospects.

Valeriya Mykhaylova

Dynamical and transport properties of deconfined matter in hot QCD

We study transport properties of the deconfined matter with different number of quark flavors employing the quasiparticle model (QPM). The system then consists of the dynamical gluons (and quarks) dressed by the effective temperature-dependent masses. The temperature dependence is specified by a running coupling deduced from lattice QCD thermodynamics. Utilizing kinetic theory under the relaxation time approximation, we evaluate the shear and bulk viscosity, as well as the electrical conductivity, to illustrate the role of the quasiquarks in transport properties of the QGP [1, 2]. We also evaluate the bulk to shear viscosity ratio, which illustrates the impact of dynamical quarks onto the restoration of conformal invariance. Further, we analyze the production of the charm quarks in hot QCD medium. The temperature and time evolution of the number of charm quarks is examined in perfect fluid expanding longitudinally (Bjorken scaling) and viscous QGP, whose expansion in 2+1 dimensions is dictated by the hydrodynamic simulations with the shear viscosity taken into account [3].
[1] V. Mykhaylova, M. Bluhm, K. Redlich and C. Sasaki, Phys. Rev. D 100 (2019)
[2] V. Mykhaylova, C. Sasaki, Phys. Rev. D 103 (2022)
[3] J. Auvinen et al., Phys. Rev. C 102 (2020)

Presentation (pdf)

David Blaschke (IFT)

The German Centre of Astrophysics in Görlitz

On Thursday, 29.09.2022, the German Minister of Education and Research has announcedthat the German Center for Astrophysics (DZA) will be built in Görlitz with more than 1.1 billionEuros by 2038. Close cooperation with the University of Wroclaw as an academic partnerinstitution with training and research in astrophysics is planned. Around 1,000 employees, 350 of whom are scientists, will work at the large research center. They evaluate the data from astronomical observatories from all over the world and develop new, efficient digital processes for this. Their marketing brings new jobs to the region.The German federal government and the state governments of Saxony and Saxony-Anhalt want to use the new center to accelerate structural change in the region, which was originally dominated by lignite mining. I will give an overview on the DZA project and its possible relationships to the Faculty of Physics and Astronomy of the University of Wroclaw.
Zoom Meeting
https://us04web.zoom.us/j/74620468908?pwd=89BK9FyolgQ4bngmHSwooZLzaUS9qM.1

Presentation (pdf)

Prof. Khalil Idiab, Humboldt University, Berlin

Yang-Baxter deformations of the flat space string

Symmetric space sigma models (SSSM) and their Yang-Baxter deformations are integrable, which makes them useful in providing exact results in the AdS/CFT correspondence. Much is known about these integrable models at classical level, but difficulties with quantization makes it hard to make general statements about their quantum integrable structure. By considering deformations of the flat space sigma model, with non semi-simple Poincaré symmetry, it turns out one can find deformed models that can be canonically quantized (plane waves), enabling future investigation of their quantum structure. As a first step, this requires extending Yang-Baxter deformations of SSSMs to cases with non semi-simple symmetry groups, this will be the main objective of the talk.

Etele Molnar (ISE SSF, WFA UWr)

Multicomponent relativistic dissipative fluid dynamics from the Boltzmann equation

We review the derivation of the fluid-dynamical equations of motion from kinetic theory. Applying this method we derive multicomponent relativistic second-order dissipative fluid dynamics from the Boltzmann equations for a reactive mixture of NS particle species with NQ intrinsic quantum numbers (e.g. electric charge, baryon number, and strangeness). The resulting transient fluid-dynamical equations are formally similar to those of a single-component system, but feature different thermodynamic relations and transport coefficients, which contain the microscopic interactions of all components.

mgr Arkadiusz Bochniak, prof. Andrzej Sitarz (joint talk) (UJ)

Physics from spectral triples with non-product geometries

We'll briefly review the concept of applying the construction of Connes' spectral triples to the Standard Model and gravity which goes beyond the commonly assumed product of two spectral triples. The application to the SM allows having no fermion doubling, explains naturally CP violation and no strong symmetry breaking while the gravity part leads to interesting models similar to bimetric modifications of gravity.

Prof. Maciej Dunajski, Cambridge University

State reduction, gravity, and twistor theory

A non-relativistic limit of twistor theory provides a non-local description of Newtonian space-times. It is argued that combining this non-locality with the non-locality of quantum mechanics provides a mechanism for Penrose's proposal linking classical gravity and quantum wave function collapse.

Zoom Meeting
Meeting ID: 913 0439 4962
Passcode: U8fUwJ

Prof. Maciej Dunajski (University of Cambridge)

Four facets of geometry

The study of geometry is at least 2500 years old, and it is within this field that the concept of mathematical proof - deductive reasoning from a set of axioms - first arose. The lecture will present four areas of geometry: Euclidean, non-Euclidean, projective geometry in Renaissance art, and geometry of space-time inside a black hole.

Daniel Bemmerer (Dresden)

Nuclear astrophysics at the Felsenkeller underground laboratory in Dresden

Nuclear astrophysics aims to understand the production of the chemical elements in the universe. The field has strong links to cosmology, for example in Big Bang nucleosynthesis and the study of neutron star precursors. The talk will review the progress of the Felsenkeller shallow-underground ion accelerator lab in Dresden, Germany. Several nuclear reactions of astrophysical relevance are under study in this low-background setting. In addition, the talk will present a new EU-supported Starting Community of research infrastructures for nuclear astrophysics, ChETEC-INFRA. ChETEC-INFRA networks and provides access to a diverse set of related infrastructures in EU and associated countries.

Agnieszka Sorensen (Seattle)

Measuring the speed of sound in matter created in heavy-ion collisions

Heavy-ion collision experiments offer a unique opportunity to study the properties of hot and dense nuclear matter in a laboratory. In particular, many current analyses are directed towards uncovering the phase diagram of QCD. In these studies, enhanced fluctuations of baryon number are given considerable attention as possible signatures of the QCD critical point. In this talk, I will show that using fluctuations in the number of detected particles may also allow one to measure a fundamental characteristic of the studied systems: the speed of sound and its logarithmic derivative with respect to the baryon number density. I will discuss what we might learn from existing data and what remains to be done to connect experimental results with properties of dense QCD matter.

Presentation (pdf)

Falk Hassler (IFT)

How Strings May Heal the Fabric of Cosmos

Over the last years, we could witness stunning experimental evidence for the existence of black holes. At the singularity in their centre, gravitational forces are so strong that they even rip spacetime apart. Our conventional approach to gravity, general relativity, fails here and must be replaced by a new framework. Substituting point particles by extended strings is a potential cure. However, it is currently not feasible to obtain direct conclusions from this idea and explain what happens at the singularity. To rectify this situation, I show how four different arenas of string theory (dualities, geometry, supergravity, and integrability) are secretly governed by one central concept, Generalised Homogeneous Spaces (GHS). They are the string's version of homogeneous spaces with a remarkable variety of new properties. I summarise my current efforts to incorporate their quantum corrections due to the extended nature of the string and how they eventually should resolve singularities in black holes or cosmology.

Presentation (pdf)

prof. Matthias Kaminski (University of Alabama, USA)

Quantum Dynamics far from Equilibrium

A quantum computer stores information in a large number of interacting quantum bits, qubits. These qubits need to be written and read fast enough, because they come with an "expiration date". This is caused by a quantum mechanical effect called "decoherence" which destroys the desired "quantum entanglement". This constitutes a fundamental open problem, namely to understand and control the dynamics of rapidly changing quantum many body systems, i.e. systems far away from being in equilibrium. Remarkably, we can experimentally generate such states of matter in heavy-ion-collisions for example at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory, Upton, NY, at the Large Hadron Collider, CERN, Geneva, Switzerland, and soon at the Facility for Antiproton and Ion Research (FAIR), GSI, Darmstadt, Germany. The underlying physical concepts are the same, although, of course, the energy range, temperature and many other parameters are vastly different. Focusing on the common features of these two distinct systems will lead us to the discovery of the essential fundamental concepts that govern quantum dynamics far from equilibrium. This constitutes a powerful fundamentally novel approach to problems in quantum computing, leveraging the wealth of knowledge, methods and experiments from particle physics.

Presentation (pdf)

Johann Rafelski, Department of Physics, The University of Arizona

Special Relativity and Strong Fields: A personal perspective

All theories in physics satisfy the principle of relativity. The relativistic formulation of electromagnetic interactions is for historical reasons called Special Relativity (SR) and that of gravity GR.SR experiences a renaissance as a discipline and is rapidly evolving: We are probing the acceleration/strong electromagnetic field frontier in relativistic heavy ion experiments, and thinking ahead to the very high intensity laser-particle interaction. These frontier domains of physics are demanding researchers properly trained in SR. Yet this old domains of physics is poorly represented in many introductory text book used by out of field lecturers. The unfinished formulation of SR when strong fields are present compounds the student confusion. A new book "Modern Special Relativity" https://link.springer.com/book/9783030543518 provides historical background as motivation to return to the topic and aims at a very elementary level to resolve some of the misunderstandings while motivating students to embark on study of the acceleration frontier.

Presentation (pdf)

Yuri Sinyukov, Bogolyubov Institute, Kiev & ITP University of Wroclaw

Thermalization, evolution and observables in integrated hydrokinetic model of A+A collisions

A further development of the evolutionary picture of A + A collisions, which we call the integrated hydrokinetic model (iHKM), is proposed. The model comprises a generator of the initial state, prethermal dynamics of A + A collisions leading to thermalization, subsequent relativistic viscous hydrodynamic expansion of quark-gluon and hadron medium, its particlization, and finally the hadronic UrQMD cascade. We calculate for different centralities midrapidity charged-particle multiplicities, pion, kaon, and (anti)proton spectra, charged-particle elliptic flows, pion and kaon interferometry radii, source functions for different hadron pairs and use the latter to extract the scattering lengths for baryon-(anti) baryon pairs as well as predict (anti-)proton–hyperon correlation functions for Pb + Pb collisions at the LHC. Also we analyze Phi and K* resonance production and their decays in hadronic medium.

Presentation (pdf)

Natalie Jachowicz (Ghent)

Modeling neutrino-nucleus cross sections for accelerator-based experiments

Worldwide, neutrino experiments are preparing for a decisive search in the exciting investigation of the matter dominance that characterizes our universe. Collaborations as HyperKamiokande and DUNE are aiming for a precision analysis of neutrino oscillations and the determination of the CP violating phase. A common feature of these accelerator-based oscillation experiments, is that they rely on neutrino-nucleus cross sections to 'count' the neutrinos in their near and far detectors to allow them to obtain to infer oscillation information. This brings along the need for detailed predictions of the interaction probability for different (anti)neutrino flavors as a function of energy. In this talk, I will present the Ghent program on neutrino-nucleus cross section modeling, that is aiming at a description of neutrino-nucleus interactions over a broad energy range, with models ranging from low energy coherent processes over collective nuclear excitations and quasielastic predictions, to two-nucleon knockout processes and pion production.

Join Zoom Meeting
https://zoom.us/j/92068088302?pwd=amVsVS9FR2kwMkwxaEwxYlBDaE9oQT09

Jan Sobczyk

Pytania związane z niedawnymi pomiarami z MicroBooNE

Omówię jak dobrze NuWro odtwarza, czy też nie odtwarza, niedawne pomiary przekrojów czynnych opublikowane przez eksperyment MicroBooNE i zastanowię się co z tego może wynikać. Seminarium będzie miało charakter roboczy, ale postaram się, by było zrozumiałe również dla nie specjalistów.

Prof. Maciej Nowak (Jagiellonian University, Kraków)

2021 Nobel Prize in Physics for Complexity

In the talk I will briefly explain the importance of complex systems, and then I will concentrate mainly on the contributions of Giorgio Parisi to this area, with special emphasis on the replica symmetry breaking in spin glasses and beyond.

Prof. Richard Kermer (Sorbonne Paris)

Hundred Years of Relativity Theory in Poland

The history of the Theory of Relativity in Poland is related primarily to the Warsaw school, and began in pre-war times. Then Leopold Infeld's return to Poland played a great role in raising the next generation of relativists; including Andrzej Trautman. Further contributions of Polish physicists and mathematicians to the development of Relativity Theory will be presented along with its applications, particularly in astrophysics. The achievements of the Krakow school will also be mentioned.

Prof. Richard Kerner, Sorbonne, Paris

Lorentz covariance from discrete symmetries Z2 and Z3

Our aim is to derive the symmetries of the space-time, i.e. the Lorentz transformations, from symmetries of the interactions between the most fundamental constituents of matter, in particular quarks and leptons. We show how the discrete symmetries Z_2 and Z_3 combined with the superposition principle result in the SL(2, C) and SU(3) symmetries. The role of Pauli's exclusion principle in the derivation of the SL(2, C) symmetry is put forward as the source of the macroscopically observed Lorentz symmetry. Then Pauli's principle is generalized for the case of the Z_3 grading replacing the usual Z_2 grading, leading to ternary commutation relations. We present the cubic and ternary algebras which are a direct generalization of fermionic algebras with Z_3-grading replacing the usual Z_2-grading. Elementary properties and structures of such algebras are discussed, with special interest in the low-dimensional ones, with two generators only. Invariant cubic forms on Z_3-graded algebra with two generators are introduced, a possible description of the isospin. It is shown how a Z_3-graded generalization of the SL(2,C) group arises naturally as the symmetry group preserving the Z_3-graded ternary isospin algebra. Vectorial and spinorial representations of the generalized Z_3-graded. Lorentz algebra are briefly discussed.

Jan Perina (Palacky University, Olomouc, Czech Republic)

Identification and quantification of nonclassicality of experimental optical fields

Nonclassical optical fields are useful in numerous applications at present. Identification and quantification of their nonclassicality thus represents an important task. In the talk, identification of nonclassicality of optical fields via the so-called nonclassicality witnesses will be discussed in general using the experimental intensity moments as well as the measured photocount histograms (photon-number distributions). Different methods for the derivation of nonclassicality witnesses will be discussed and compared considering a general N-mode optical field. Applicability of the nonclassicality witnesses based on intensity moments and elements of photocount histograms (photon-number distributions) will be discussed. Quantification of the nonclassicality in relation to the discussed nonclassicality witnesses and using the concept of the Lee nonclassicality depth will also be mentioned. Photocount and photon-number distributions belonging to several types of experimental single mode, two-mode as well as three-mode non-classical optical fields (sub-Poissonian fields, fields with (anti-)correlations in photocounts and photon numbers) will be used to demonstrate the general results.

Dr Pasi Huovinen

The egg of excellence: modeling of heavy-ion collisions

Recently University of Wrocław established the Incubator of Scientific Excellence - Centre for Simulations of Superdense Fluids, as part of the Faculty of Physics and Astronomy. In this talk I will describe the scientific mission of the Incubator: modeling of the evolution of strongly interacting matter formed in ultrarelativistic heavy-ion collisions, and what we have learned of the properties of such matter so far.

Dr. Shota Shibagaki (Fukuoka, Japan)

Multi-Messenger Signals from Non-Rotating and Rapidly Rotating Stellar Core Collapse

Gravitational waves and neutrinos emitted from the supernova core carry the imprints of the dominant multi-dimensional dynamics inside the proto-neutron star. We explored the impacts of fluid instabilities on the gravitational wave and neutrino signals from a progenitor with various rotations, and revealed characteristic features of gravitational waves and neutrinos and their correlation. In this talk, I show the results of the time-frequency analysis of the gravitational wave and neutrino signals obtained from our simulations and make a comparison between them to find their correlation. I also discuss the detectability of the characteristic features of the gravitational waves and those of the neutrinos.

Andrzej Szczepkowicz, Dmytro Konakhovych, Damian Śnieżek

Rozwiązywanie równań Maxwella w strukturach dielektrycznych

Chociaż równania Maxwella mają już 150 lat, to na użytek współczesnej techniki wciąż poszukuje się nowych ich rozwiązań; poszukuje się także nowych struktur optycznych, dla których istnieją pożądane typy rozwiązań. Przykładem może być intensywnie rozwijająca się technika optycznych akceleratorów cząstek, w której czynnikiem napędzającym cząstki, zamiast dotychczas stosowanych mikrofal, jest światło laserowe. Jedną z nowinek w dziedzinie projektowania dielektrycznych struktur przyspieszających jest tzw. projektowanie odwrotne (photonic inverse design), w którym algorytmy zastępują intuicję projektanta.

dr Zhandos Moldabekov (CASUS, Görlitz)

The Physics of Inhomogeneous Warm Dense Matter

Warm dense matter (WDM) is an interdisciplinary field between plasma physics, condensed matter physics, high pressure science, inertial confinement fusion, planetary science, and materials science under extreme conditions [1-3]. Therefore, WDM is a complex regime to which neither ordinary condensed matter theory nor plasma theory are applicable. Due to relatively well developed theoretical and computational methods for homogeneous states, most of the initial studies were focused on uniform WDM. However, recent introduction of THz lasers [4], the novel seeding technique to reach high intensities [5], and laser pumping of a sample with a predesigned periodic grating structure [6] allows us to generate inhomogeneous states. Therefore, in this talk the results will be presented for collective oscillations in inhomogeneous WDM. Additionally, the non-linear density response of electrons and applicability of various exchange-correlation functionals such as LDA, GGA, and meta-GGA will be discussed. The analysis of the quality of the KS-DFT approach based on different exchange-correlations functionals is performed by comparing to QMC data. Finally, the quantum fluid theory of inhomogeneous quantum electrons will be presented. The results on the first ab inito study of the many-fermion Bohm field will be shown. The latter has impact going well beyond WDM, since it is key quantity of Bohmian quantum mechanics.
[1] A. Ng, IEEE International Conference on Plasma Science (Cat. No.02CH37340), 2002, pp. 163-, doi: 10.1109/PLASMA.2002.1030367
[2] F. Graziani, M. P. Desjarlais, R. Redmer, and S. B. Trickey, Frontiers and Challenges in Warm Dense Matter (Springer, 2014)
[3] V. E. Fortov,Extreme States of Matter (Springer, Heidelberg, 2016)
[4] B.K. Ofori-Okai, et al., J. Inst13, P06014 (2018)
[5] T Kluge, et al., Phys. Rev. X 8, 031068 (2018)

Dr Oleksii Ivanytskyi

Relativistic density functional approach to a unified description of quark-hadron matter

The principal element of a unified description of strongly interacting matter within effective theories is the hadronization of quarks at low temperatures and baryonic densities, while the partonic degrees of freedom are being suppressed in this regime. I present a novel approach to attack this problem, which is formulated based on a relativistic density-functional motivated by the string-flip model. Dynamical restoration of chiral symmetry within this approach is ensured by construction of the density functional. The low density/temperature suppression of quark degrees of freedom is provided by the divergence of the corresponding self-energy already at the mean-field level. I also discuss the connection of the present approach to a Nambu-Jona-Lasinio-type model with density dependent (pseudo-)scalar coupling. Supplemented with the vector repulsion and diquark pairing channels it is applied to model cold quark matter. The corresponding couplings are limited by confronting the results of modeling compact stars with quark cores to the observational data. This allows to construct the mean-field phase diagram of strongly interacting matter. Effects of hadronization of strongly interacting matter are considered as a result of quark correlations beyond the mean field. The correlations caused by (pseudo-)scalar interaction channels are considered within the Gaussian approximation. This explicitly introduces mesonic states into the model. Their contribution to the thermodynamic potential is analyzed within the Beth–Uhlenbeck framework. Due to the different response of the mass spectrum of bound and continuum states to changes of the medium properties the Mott dissociation of mesonic bound states occurs and is interpreted as physical mechanism of the deconfinement transition.

Eliazer Piasetzky (Tel Aviv)

Short-range correlations in nuclear systems

Nucleons in nuclei with momentum greater than the nuclear Fermi momentum are predominantly due to close-proximity neutron-proton pairs, which interact via a strong short-range force. I will discuss these close-nucleon and their importance to the study of neutron stars and the modification of the internal structure of nucleons bound in nuclei.

Presentation (pdf)

Oleksii Ivanytskyi (IFT)

Revisiting the Polyakov Loop Nambu-Jona-Lasinio model at finite baryonic density

Phenomenological confinement of quarks within effective approaches is an important ingredient of modeling the equation of state of strongly interacting matter. Coupling quarks to the Polyakov loop, which is an exact order parameter in the pure gauge case, serves as an efficient mechanism for such phenomenological confinement at finite temperatures. I present the Polyakov Loop coupled Nambu-Jona-Lasinio model revisited in order to maintain the Polyakov loop dynamics at vanishing temperature, which is the most interesting for astrophysical applications. This is done by re-examing potential for the deconfinement order parameter at finite baryonic densities. Secondly, and the most important, I explicitly demonstrated that naive modification of this potential at any temperature is formally equivalent to assigning a baryonic charge to gluons. The developed general formulation of the present model is free of the discussed defect and, on the other hand, can be justified within the density functional approach. The Polyakov loop potential is normalized to asymptotic of the QCD equation of state given by the O(α2s) perturbative results. I also demonstrate that incorporation of the Polyakov loop dynamics to the present model sizably stiffens the quark matter equation of state giving a positive feedback to the problem of existence of heavy compact stars with quark cores.

Marek Szczepańczyk (Florida)

Gravitational waves from the next galactic core-collapse supernova

Core-collapse supernovae (CCSNe) are one of the most spectacular phenomena known in the Universe. While we know that they are explosions of massive stars, the mechanism of these explosions is not yet well understood. The detection of gravitational waves (GWs) will allow to directly probe the CCNS engine, helping to understand the explosion mechanism and shed light on the other questions about the nature of these phenomena. I will present a detailed study of a wide range of GW signatures derived from the multidimensional CCSN simulations. Then, I will provide prospects of detecting GWs with the advanced GW detectors, indicating that the signals from neutrino-driven explosions and the explosions from the rapidly rotating progenitors could be detected up to an average distance of 10 kpc and 100 kpc, respectively, and an estimated minimum signal-to-noise ratio of 10-25 is needed for the signals to be detected. I will discuss the accuracy and the challenges of reconstructing the waveforms. Finally, I will talk about how well particular emission processes in CCSN can be reconstructed for a detected GW signal.

Presentation (pdf)

Jakub Jankowski (IFT)

Hydrodynamic attractors in heavy ion collisions

I will review the concept of hydrodynamic attractors and their properties, focusing on applications in heavy-ion collision experiments. One direct consequence of hydrodynamic attractors is a general relation between the initial state energy and the produced particle multiplicities measured in experiments. When combined with an ab-initio model of energy deposition it provides constraints on far-from-equilibrium early time dynamics in a form of quantitative estimates of pressure anisotropies. This strongly suggests that assuming free streaming prior to hydrodynamization is not necessarily compatible with a generic initial state model and that features of the pre-hydrodynamic flow need to be matched with the model of the initial state. Talk based on: 2012.02184

Presentation (pdf)

Armen Sedrakian (IFT)

Universal relation for neutron stars with heavy baryons at finite temperature

We conjecture and verify a set of universal relations between global parameters of hot and fast-rotating compact stars, including a relation connecting the masses of the mass-shedding (Kepler) and static configurations. We apply these relations to the GW170817 event by adopting the scenario in which a hypermassive compact star remnant formed in a merger evolves into a supramassive compact star that collapses into a black hole once the stability line for such stars is crossed. We deduce limits on the maximum mass of static, cold neutron stars within this scenario.

Presentation (pdf)

Rafał Kowalski (INP PAN)

Multiscale financial correlations in Ising-inspired agent-based models

The financial market is an example of a complex system with an enormous number of dependencies and intricate correlations between components. Analysis of such systems requires applying sophisticated mathematical tools, while its modelling using a traditional top-down approach is difficult. In this context, financial markets are similar to thermodynamic systems that can be quantitatively described and modelled using techniques applied in statistical physics. We demonstrate how to quantify nonlinear dependencies in financial time series using complex network and multifractal analysis techniques. Obtained multifractal spectra are broad and often reveal left-hand side asymmetry, indicating great complexity of analysed signals, while cross-fluctuations functions obey a power law over a large range of scales suggesting nonlinear cross-dependencies between financial assets. Next, we present an authorial, Ising-inspired agent-based model of the financial market, which combines local and global interactions, allowing generation of multifractal time series. Moreover, the framework incorporates multiple subsystems and facilitates modelling nonlinearly cross-correlated signals thereby enabling simulations of entire financial indices, which in turn has a lot of potential for practical applications.

Presentation (pdf)

Zbigniew Haba

Decoherence and noise in an environment of photons and gravitons

I shall first discuss the electromagnetic environment as it appears in classical and quantum mechanics. Its role in the modification of the Hamiltonian formulation of classical and quantum mechanics is well-known. Only perturbative electrodynamics is relevant in such a problem. I argue that in a similar way perturbative (classical or quantum) gravity has some observable consequences in a measurement of CMB temperature fluctuations and detection of gravitational waves.

Presentation (pdf)

Hannah Elfner (FIAS Frankfurt)

Exploring the QCD phase diagram: Approaching the phase transition from the hadronic side

Colliding heavy ions at ultra-relativistic energies offers access to strongly-interacting matter under extreme conditions. In this talk, I will present the state-of-the-art for the dynamical description of heavy-ion reactions at lower beam energies and introduce the hadronic transport approach SMASH (Simulating Many Accelerated Strongly-interacting Hadrons). A detailed theoretical description of the whole dynamics is required to connect fundamental QCD input to experimental observables. Beyond some recent results, I will focus on the transport coefficients of hadronic matter at finite temperatures and densities calculated within the SMASH hadronic transport approach.

Presentation (pdf)

Benjamin Wehmeyer (Research Centre for Astronomy and Earth Sciences, Budapest)

Galactic Chemical Evolution of r-process elements

The origin of the heaviest elements is still uncertain. For the rapid neutron capture process ( r-process), multiple sites have been proposed, e.g., neutron star mergers and (sub-classes of) supernovae. R-process elements have been measured in a large fraction of metal-poor stars. Galactic archaeology studies show that the r-process abundances among these stars vary by over 2 orders of magnitude. On the other hand, abundances in stars with solar-like metallicity do not differ greatly. This leads to two major open questions: 1. What is the reason for such a huge abundance scatter of r -process elements in the early galaxy? 2. While the large scatter at low metallicities might point to a rare production site, why is there barely any scatter at solar metallicities? In this talk, I will discuss chemical evolution scenarios that provide an explanation for the observed abundance features of r-process elements in our Galaxy. Further, I will explain how adding short lived radioisotopes to the model can help to further constrain the r-process and other processes.

Presentation (pdf)

Joanna Sobczyk (Universität Mainz)

Towards ab-initio computations of neutrino scattering on medium-mass nuclei

In my talk I will give an overview of the recent progress that has been made in describing neutrino-nucleus scattering within the ab-initio coupled-cluster framework, combined with the Lorentz integral transform. These techniques open the door to obtaining nuclear responses (and consequently cross-sections) for medium-mass nuclei starting from first principles. A series of steps has been made in this direction. Firstly, the nuclear 1- and 2-body currents have been re-derived and checked for the case of neutrino-deuteron scattering. Afterwards, the Coulomb sum rule of 16O has been calculated, introducing a new technique to remove the center-of-mass contamination. Most recently, we have calculated for the first time the longitudinal response of 40Ca. These developments allow to extend the applicability of ab-initio methods in the field of neutrino-nucleus interactions to medium size nuclei, contributing this way directly to the neutrino oscillation program.

Presentation (pdf)

Xun-Jie Xu (Université Libre Bruxelles, Brussels, Belgium)

Dark forces from right-handed neutrinos

Right-handed neutrinos are often considered as a portal to new hidden physics. It is tempting to consider a gauge singlet scalar that exclusively couples to right-handed neutrinos. Although such a scalar does not couple to normal matter at tree level, loop- induced effective interactions are inevitable. And the magnitude of the loop-induced couplings coincidentally meets the current sensitivity of fifth-force searches. In particular, the loop-induced coupling to muons could be tested in the recent LIGO observations of neutron star mergers. Talk based on 2007.01893, 2012.09980

Presentation (pdf)

Marek Abramowicz (CAMK Warsaw)

Gravitational waves from ultra-compact stars

I present a recent analytic solution (Horak & Abramowicz 2021, unpublished) that describes quasi-normal modes of super-compact stars close to the Bondi limit. In the LIGO-Virgo terminology these are wave-fronts and frequencies of ringdowns and echoes. They may help distinguishing between black hole versus non black hole origin of the waves.

Presentation (pdf)

Giacomo Rosati, Tomasz Pawłowski

GR: Quantum spacetime symmetries: between theory and phenomenology of quantum gravity
TP: Cosmological perturbations and black hole singularities in loop quantization

Giacomo Rosati
I will present the recently (OPUS17) awarded project "Quantum Gravity and Deformed Quantum Fields", written in joint collaboration with prof. Kowalski- Glikman. The project is at the interface between more fundamental approaches to quantum gravity and quantum gravity phenomenology. The study of deformed relativistic symmetries characterizing quantum field theories on the emerging (noncommutative) quantum spacetime bridging the two.

Tomasz Pawłowski
I will briefly present the research line I represent - search for physical predictions on loop quantum cosmology/gravity in context of recently awarded project NCN OPUS "Cosmological perturbations and black hole singularities in loop quantization".

Maciej Lewicki

Charged hadron production in central Ar+Sc collisions at the CERN SPS

PhD Thesis defense

Jan Sobczyk

Neutrino Physics Division - research activity

I will give an overview of the research activity in the Neutrino Physics Division.

Krzysztof Redlich & David Blaschke

Matter under Extreme Conditions

In the first part of the seminar we present the research directions of the Division of Theoretical Particle Physics that is devoted to investigations of matter under extreme conditions and their applications to the phenomenology of QCD phase transformations in ultrarelativistic heavy-ion collisions and in the Astrophysics of compact stars. The main results and achievements obtained within the past 10 years are recapitulated. The second part of the seminar we devote to the discussion of the QCD phase diagram at low temperatures, high baryon densities and large isospin asymmetries that are characteristic for matter probed in neutron stars, their mergers and supernova explosions of massive supergiant stars. The modern gravitational-wave observations of merger events by the LIGO-Virgo Collaboration allow new insights about the limits for masses and radii of compact stars which can be translated to new constraints on the equation of state. The investigation of the relationships between phase transitions in the equation of state and the astrophysical phenomena involving (proto-)neutron stars are subject to three recently obtained NCN projects that are under way in the Division.

Presentation (pdf)

prof. Marek Mozrzymas, UWr

Quantum correlations - from C* algebra and dynamics of open systems towards experimental applications in quantum optics.

I will present scientific topics studied in our Division of Mathematical Methods in Physics. In particular, I will focus on recent results in the field of quantum information theory and quantum correlations.

prof. dr hab. Jerzy Kowalski-Glikman, UWr

Towards quantum gravity

In my talk, I will first present shortly our Division of Theory of Gravity and Fundamental Interactions. Then I will spend the rest of my talk to give you a (highly personal) overview of what is hot in the theory of quantum gravity these days, explaining why the boundary/bulk correspondence is attracting so much attention, discussing briefly recent fashion trends in the black hole information problem, and mentioning quantum gravity phenomenology research program.

Presentation (pdf)

prof dr hab. Zbigniew Koza, IFT UWr

Division of Applied Computer Science & Statistical Physics

In the talk, I will present the current research projects carried out in the division, as well as the plans for the future and the problems we face.

Presentation (pdf)

dr hab. Armen Sedrakian, prof. UWr, IFT UWr

Statistical physics of strongly correlated systems

I will describe ongoing and planned work on statistical physics of strongly correlated systems and their applications to astrophysics carried out with my group. This work includes applications of statistical methods such as density functional theory and ab initio computations of equilibrium properties of nuclear systems with applications to structures of compact stars. Furthermore, it includes the development of relativistic hydrodynamics and transport in the context of neutron star mergers.

Jan Sobczyk

Oscylacje Neutrin

Rozszerzona wersja referatu wygłoszonego na jubileuszowym zjeździe w 100-lecie Polskiego Towarzystwa Fizycznego.

Prof. Andrzej Pigulski, IA UWr

Supermassive black hole in the centre of our Galaxy – 2020 Nobel prize in physics

Abstract: The Nobel prize in physics 2020 was awarded to three scientists, who share the prize for theirdiscoveries related to one of the most exotic objects in the Universe, black holes. Sir Roger Penrose showed that the general theory of relativity leads to the formation of black holes. Reinhard Genzel and Andrea Ghez discovered that the centre of our Galaxy hosts a very massive (a few millions solar masses) object. As there is no alternative explanation, the object is believed to be a supermassive black hole. I will focus on presenting the work of Genzel's and Ghez' teams, showing also how large telescopes and the development of observational techniques helped in this discovery. Finally, I will mention several hot topics in astrophysics which are related to black holes.

Presentation (pdf)

Dr Michael Bussmann, CASUS Görlitz & Helmholtz Zentrum Dresden-Rossendorf

From Data to Understanding - The Center for Advanced Systems Understanding

Research is driven by data that is not yet understood. This is apparent in fundamental research. Yet, our understanding of real life phenomena opens up a new view on what it means to understand data. Today, we are facing a wealth of highly detailed, high quality scientific data from large scale research facilities, observatories, sensor arrays or satellites. At the same time, Exascale computing opens up new paths to simulate these systems including all the details we find in our observations. This introduces a new challenge, namely mastering complexity. This is already visible in the rise of Artificial Intelligence methods. Yet, we are faced with a situation where the human understanding of the interrelation of the interacting parts in a complex system require new digital methods to understand their structure and dynamics. In this talk we cover some examples on how digital methods can help to shed new light on highly complex systems and how developing these methods can foster interdisciplinary research. Join Zoom Meeting https://zoom.us/j/94480626446?pwd=SXViWXNpZkZxQVhlb1ZYR3ZtUXJidz09 Meeting ID: 944 8062 6446 Passcode: 6eNA5Y

Kajetan Niewczas

Modeling two-nucleon knock-out in neutrino-nucleus scattering

Accelerator-based neutrino oscillation experiments rely on the description of neutrino interactions with bound nucleons inside atomic nuclei. Neutrino fluxes used in modern experiments (T2K, NOvA, MiniBooNE) are peaked in the 1–5 GeV energy region where one can identify contributions from multiple interaction channels and various nuclear effects. The neutrino-nucleus cross sections in this region are known with a precision not exceeding 20% and have to be investigated further in pursuing to reduce systematic errors in oscillation measurements. The Ghent group focuses on providing a consistent description of this process in the intermediate energy region. Various interaction channels are modeled, including the two-nucleon knock-out (2p2h) that is known to provide one of the least controlled sources of uncertainty. The 2p2h final states are obtained via two mechanisms: short-range correlations [Phys.Rev.C 94 (2016) 024611] and meson-exchange currents [Phys.Rev.C 95 (2017) 054611]. Refined treatment of nuclear effects is achieved by constructing both bound-state and continuum nucleon wave functions through a Hartree-Fock calculation with an effective Skyrme-type interaction. I will present the results of the aforementioned references, as well as the current status and prospects of the project.

Vytautas Dūdėnas (Vilnus University)

Neutrinos in the Grimus-Neufeld model

The Grimus-Neufeld model is a two Higgs doublet model, extended with a single heavy seesaw neutrino. This setup allows for explaining both of the neutrino mass differences with the seesaw mechanism and radiative mass generation. Since this model is rather minimal, the neutrino Yukawa couplings have only few parameters. Connecting radiative mass generation with the seesaw mechanism, almost all of the neutrino Yukawa couplings can be expressed in terms of the neutrino mixing matrix and the neutrino masses. These Yukawa couplings contribute to physical observables, such as lepton flavor violation. I will introduce to the model by going through the two mass generation mechanisms and show how we can relate the neutrino Yukawa couplings to measured neutrino parameters at one loop.

mgr Beata Kowal, IFT UWr

Polarization effects in neutrino-nucleon interactions

Quasielastic (QE) neutrino-nucleon scattering and single pion production (SPP) are important processes in neutrino oscillation experiments. Reconstruction of the neutrino energy distribution bases on the analysis of QE scattering, while SPP is one of its main background processes. Polarization observables are well suited for studying the axial nucleon form factor and non-standard interaction. They are also sensitive to the details of the SPP models. In particular, the normal polarization observable is dominated by the interference between resonant and nonresonant contributions. We considered a polarized target, the polarization of charged lepton and recoil nucleon. In the case of QE process, multispin observables were examined. The presentation bases on the results published in Phys.Rev.D 101, 073002, Phys.Rev.D 97, 013001 and Phys.Rev.D 99, 053002.

Krzysztof Graczyk

Machine learning in quantum matter and high energy physics

I will review two recent papers: arxiv:2005.08582 and arxiv:2003.11040 about applications of modern machine learning methods to quantum matter and high energy physics. The seminar is going to have informal character.

dr Dmitry Zhuridov, IFT UWr

Neutrino-Electron Scattering in NuWro

Wrocław Neutrino Event Generator (NuWro) is being developed since 2006 at the University of Wrocław. This Monte Carlo generator includes many types of dynamics for various cases of neutrino scattering on nucleons and nuclei. A subleading piece that was missing so far is the neutrino scattering on (atomic) electrons. I recently implemented it to NuWro. Adding this piece helps to reduce the backgrounds and better understand the whole neutrino scattering kitchen. This new dynamics includes the charged current and neutral current interactions, as well as their interference. Ten possible final states can be generated there. I will present the first NuWro results for this new scattering channel.

Jan Sobczyk

Reweighting of Final State Interactions

I will present simple mathematical models illustrating the idea of reweighting of Final State Interactions.

dr Piotr Biskupski, IBM Polska s.a.

The future is quantum - IBM Q experience

Tens of thousands of people around the world are using IBM quantum systems and Qiskit to explore the exciting world of quantum computing in collaboration with the IBM Quantum team of experts. Together, we're making quantum computing accessible to everyone - accelerating the pace of advancement in research institutions, industry labs, and classrooms. Check the IBM Quantum Experience to get access to quantum devices, development tools, and learning resources. Learn more about the different ways to connect with IBM Quantum, and create a free account to start using our quantum tools today. Several IBM quantum devices are available to the public through our quantum cloud services. Users can access devices for free through the IBM Quantum Experience or Qiskit, and more advanced quantum systems are available to our clients in the IBM Q Network. Now all scientists around the globe can run their experiments on real hardware, check how you can use IBM Quantum and expand your experience on QC .

Election Meeting

the seminar is canceled

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Beata Kowal

Polarization effects in neutrino-nucleon interactions (continued)

Quasielastic neutrino-nucleon scattering and single pion production are important processes in neutrino oscillation experiments. I will show that polarization observables are well suited for studying the axial nucleon form factor, non-standard interaction and testing single pion production models. My presentation bases on the results published in Phys.Rev.D 101, 073002, Phys.Rev.D 97, 013001 and Phys.Rev.D 99, 053002.

prof. Jan Ostrowski, ENS Lyon

Physical cosmology by James Peebles

2019 Nobel Prize in Physics was shared by Michel Mayor, Didier Queloz and James Peebles. Although none of these verdicts is controversial, it is the recognition of prof. Peebles and his contribution to cosmology that is unusual as it was given for the lifetime achievement rather than a single discovery. Indeed, modern physical cosmology bears traces of Peebles' ideas and intuition in almost all of its branches. In my talk I will give a summary of current state of knowledge about the Universe with an emphasis on Peebles' 'curiosity-driven research'.

Beata Kowal

Polarization effects in neutrino-nucleon interactions

Quasielastic neutrino-nucleon scattering and single pion production are important processes in neutrino oscillation experiments. I will show that polarization observables are well suited for studying the axial nucleon form factor, non-standard interaction and testing single pion production models. My presentation bases on the results published in Phys.Rev.D 101, 073002, Phys.Rev.D 97, 013001 and Phys.Rev.D 99, 053002.

dr Giacomo Rosati, IFT UWr

Testing quantum spacetime with gamma-ray-burst neutrinos and photons

In some models of quantum-gravity-inspired quantum spacetimes, relativistic symmetries are modified (deformed or broken) at the Planck scale, so that spacetime itself might behave like a dispersive medium for particle propagation (in-vacuo dispersion). The long (cosmological) distance traveled by ultra-relativistic particles emitted by transient astrophysical sources could provide a huge source of amplification for the tiny (Planckian) effects, offering a precious opportunity for experimental tests. I discuss recent results that, combining observations of astrophysical neutrino, supposedly emitted by gamma-ray-bursts (GRB), and GRB-photons, show how the same feature could apply over a wide range of energies.

Kajetan Niewczas

Electroweak single-pion production off the nucleon: effective implementation in Monte Carlo event generators (part 2)

Neutrino-induced single-pion production (SPP) provides an important contribution to neutrino-nucleus interaction, ranging from intermediate to high energies. There exist a good number of low-energy models in the literature to describe this process in the region around the Delta resonance. However, their implementation in the Monte Carlo event generators, that are used in accelerator-based neutrino oscillation experiments, is still very limited. I will present a framework exhaustively described in Ref. [J.E. Sobczyk et al., Phys.Rev. D98 (2018) 073001] and its potential to be used for generic and optimized implementations of SPP models. The discussion will be exemplified using the model developed by the Ghent group [R. González-Jiménez et al., Phys.Rev. D95 (2017) 113007] and its implementation in NuWro Monte Carlo generator.

prof. Armen Sedrakjan, IFT UWr

Neutron star mergers: Equation of state and dissipative hydrodynamics.

I will discuss the recent progress in the exploration of dense matter equation of state and fluid dynamics which is largely motivated by the recent multi-messenger observation of a binary neutron star merger. In the first half of the talk, the focus will be on the relativistic density functional approaches to the dense nuclear matter with the hyperonic and delta-resonance degrees of freedom. It will be argued that the astrophysical data is consistent with the appearance of heavy baryonic degrees of freedom in compact stars. In the second part of the talk, I will discuss some transport phenomena in neutron stars and the need of including dissipative processes in modeling the fluid dynamics of binary neutron star merger such as the neutrino driven bulk viscosity.

Dmitry Zhuridov

Neutrino Electron Scattering: New Channel Implementation to NuWro

I will discuss my progress in adding the following interaction dynamics to the NuWro package: neutrino-electron scattering in the framework of the Standard Model. This new channel includes six subchannels that differ from each other by the type of initial neutrino or antineutrino. Ten possible final states are produced there in the processes nu + e -> nu' + l and nubar + e -> nubar' + l, where charged current, neutral current and their interference are present. Prior to the implementation I made a separate C++ code to generate events from this dynamics and make histograms. First NuWro results for this new channel, visualized by ROOT, will be presented.

Jarosław Pawłowski, PWr, Wydział Podstawowych Problemow Techniki, Katedra Fizyki Teoretycznej

Solid-state quantum computing - a simple overview

In the seminar I will deal with the idea of quantum computing (QC). I will start with a brief description of the idea of quantum information processing, quantum parallelization and its advantage over the "classical" approach and show where it will be potentially useful. What kind of computational problems are already implemented in quantum and how they outperform classical ones. Then I will move to hardware issues and summarize the great problem of QC implementation. I will focus primarily on the solid-state QC, as it is considered to be easily scalable and integrable with classical semiconductor electronics. I will discuss the best qubit implementation techniques (as used in Google and IBM devices) and actual problems with them, as well as other, e.g. "exotic" topological QC ideas where a multi-qubit quantum state is "protected" from decoherence by the electron bands topology. I will finish on describing my own calculations and simulations of qubit proposals in quantum structures with reduced dimensionality, i.e. semiconductor nanowires with strong spin-orbit coupling or quantum dots in graphene like structures: J. Pawłowski, New Journal of Physics 21, 123029 (2019). J. Pawłowski, D. Żebrowski, and S. Bednarek, Physical Review B 97, 155412 (2018). J. Pawłowski, P. Szumniak, S. Bednarek, Physical Review B 94, 155407 (2016)

dr hab. Grzegorz Kondrat, IFT UWr

Epidemics modeling. What can we infer from the statistics?

In the talk I will discuss how to deal with the infectious diseases by mathematical models and what the models say about possible future in these COVID days.

mgr Aleksander Kozak

Inflationary potentials from F(R) gravity in a unified hybrid metric-Palatini approach

A class of scalar-tensor theories that unify metric, Palatini and hybrid metric-Palatini gravitational actions with nonminimal interaction is investigated from the point of view of their consistency with generalized conformal transformations. It is known that such theory can be represented on shell by a purely metric scalar-tensor theory. This extends the formalism previously introduced in our last paper [1]. Exploiting properties of the Legendre transformation, we relate some viable inflationary potentials with F(R)-gravitational Lagrangians by solving corresponding Clairaut's equation. Then for given potential function various gravitational scenarios are discussed within a metric, Palatini, as well as a hybrid metric-Palatini formulations. [1] A. Kozak and A. Borowiec, "Palatini frames in scalar-tensor theories of gravity", Eur.Phys.J. C79 (2019) no.4, 335

Cezary Juszczak

Solving ordinary and partial differantial equations using neural networks (continued)

Some examples of solving ordinary and partial differental equations using neural networks and the method of Lagaris et al. will be discussed.

prof. Anna Szmyrka-Grzebyk, INTiBS PAN, Wrocław

New International System of Units

On 16 November 2018, the 26th General Conference on Weights and Measures (CGPM) approved the new International System of Units, SI. In the system, seven base units are defined by universal constants making it independent of the properties of matter, the place and time of realization of individual units. The four units - kilogram, ampere, kelvin and mole - are presently defined by the following physical constants: the Planck constant h, the elementary charge e, the Boltzmann constant k, the Avogadro constant NA.

prof. Michele Arzano

Horizon temperature without space-time

I will show how the characteristic thermal effects that observers experience in space-times possessing an event horizon, emerge already in a simple quantum system with affine symmetry living on the real line. The derivation I will present is essentially group theoretic in nature: a thermal state emerges naturally when comparing different representations of the group of affine transformations of the real line. The freedom in the choice of different notions of translation generators is the key to the Unruh effect on the real line which I will describe.

dr Mateusz Wiliński, UW

Detectability of Macroscopic Structures in Directed Networks

Identifying communities in networks is one of the funding problems in Network Science. We study the limits of this task. Specifically, we characterise the impact of introducing link directions and how it depends on their asymmetry. To this end, building on the stochastic block model, we construct a class of hardly detectable directed networks. We find closed form solutions by using, statistical physics inspired, cavity method and show an existence of a phase transition, which depends on the assortativity and asymmetry of the network.

Election Meeting

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All details: the place and time will be given and confiremed by the authoriesed person

dr Anna Pachoł, Queen Mary University of London

Digital quantum geometries

Noncommutative geometry, as the generalised notion of geometry, allows us to model the quantum gravity effects in an effective description without full knowledge of quantum gravity itself. On a curved space one must use the methods of Riemannian geometry - but in their quantum version, including quantum differentials, quantum metrics and quantum connections. The brief introduction to the general framework involving noncommutative differential graded algebra and construction of quantum Riemannian geometry elements will be provided. This framework has been applied to classification of all possible noncommutative Riemannian geometries in small dimensions (including finding explicit forms for quantum Levi-Civita connections and Riemann, Ricci and Einstein tensors), working over the field F_2 of 2 elements and with coordinate algebras up to dimension n<=3. We have found a rich moduli of examples for n=3 and top form degree 2 (providing a landscape of all reasonable up to 2D quantum geometries), including many which are not flat. Their coordinate algebras are commutative but their differentials are not. The choice of the finite field in this framework proposes a new kind of 'discretisation scheme', which we called the 'digital geometry'.

dr hab. Lech Jakóbczyk

Dydaktyczne wprowadzenie do teorii splątania pól kwantowych - kontynuacja

prof. Piotr Sułkowski, UW

Physical mathematics, string theory, and knots-quivers correspondence

String theory, apart from motivations and applications related to phenomenology, has been an important source of inspiration for mathematicians. It has led to a number of deep mathematical predictions, and even gave rise to a broad research direction, which has been referred to as a "physical mathematics" in recent years. As one such prediction, in this seminar I will present the so-called "knots-quivers correspondence" (where a "knot" means a closed loop in three dimensions, and a "quiver" is a graph that consists of nodes connected by arrows). From a physics perspective, this correspondence is the statement that two descriptions of a certain system in string theory are equivalent. From mathematical viewpoint, this correspondence is the statement that certain quantities in two seemingly unrelated mathematical fields are intimately related; in consequence it enables to prove some important conjectures in knot theory, it reveals new interesting properties of hypergeometric functions, etc.

prof. L. Dąbrowski, SISSA, Trieste, Italy

Almost commutative geometry of the Standard Model

By functions on a noncommutative (or `quantum') space one usually means a suitable algebra of operators. Then the smooth and metric structures can be described in terms of a spectral triple which involves an analogue of the Dirac operator. The Standard Model of fundamental particles in physics can be understood as the almost commutative geometry, the exterior part of which is the canonical spectral triple on a spin manifold and the finite inner part a quantum analogue of the de-Rham-Hodge spectral triple.

dr hab. Lech Jakóbczyk

Dydaktyczne wprowadzenie do teorii splątania pól kwantowych.

Sebastian Trojanowski (University of Sheffield, UK & NCBJ, Poland)

Detecting and Studying High-Energy Collider Neutrinos with FASER at the LHC

Neutrinos are copiously produced at particle colliders, but no collider neutrino has ever been detected. Colliders, and particularly hadron colliders, produce both neutrinos and anti-neutrinos of all flavors at very high energies, and they are therefore highly complementary to those from other sources. In this talk, I will discuss the recently approved Forward Search Experiment (FASER) at the Large Hadron Collider, which is ideally located to provide the first detection and study of collider neutrinos during the upcoming LHC Run 3 from 2021-23. With mean neutrino energies of 600 GeV to 1 TeV, FASER will measure neutrino cross sections at energies where they are currently unconstrained, will bound models of forward particle production, and could open a new window on physics beyond the standard model. I will also discuss some theoretical uncertainties and challenges in modeling neutrino production and interactions relevant for the FASER experiment.

dr hab. Joanna Molenda-Żakowicz, IA UWr

New perspectives on our place in the universe

The Nobel Prize in Physics 2019 was awarded to James Peebles for theoretical discoveries in physical cosmology, and jointly to Michel Mayor and Didier Queloz for the discovery of an exoplanet orbiting a solar-type star. The Mayor’s and Queloz’s discovery started a revolution in astronomy, which resulted in over 4,000 exoplanets found in the Milky Way. The strange new worlds beyond the Solar System, which are still being discovered, challenge our preconceived ideas about planetary systems. They are also forcing scientists to revise their theories of the physical processes behind the origins of planets. With numerous projects planned to start searching for exoplanets and to study their properties in more detail, we may eventually find an answer to the eternal question of whether other life is out there.

Dmitry Zhuridov

Compositeness and Democratic Neutrinos (part II)

New model of lepton and quark substructure is introduced, and its possible consequences in particle physics are discussed. In particular, the neutrino masses are predicted to be democratic, which supposes an alternative explanation of several experimental results on neutrinos

mgr Łukasz Juchnowski, IFT UWr

Quantum kinetic approach to particle production in time dependent external field

the public defence of the doctoral thesis

prof. Zbigniew Haba

Conformally flat travelling plane wave solutions of Einstein equations

Einstein equations with a conformally flat metric and ideal fluid source are discussed. It is shown that these equations have plane wave solutions. Scalar fields, electromagnetic plane waves and relativistic particles can be considered as the source of such an energy-momentum.

Dmitry Zhuridov

Compositeness and Democratic Neutrinos

New model of lepton and quark substructure is introduced, and its possible consequences in particle physics are discussed. In particular, the neutrino masses are predicted to be democratic, which supposes an alternative explanation of several experimental results on neutrinos

dr hab. Wojciech Hellwing, CFT PAN

Why and how should we test (theory of) gravity on cosmological scales

The GR is over 100 years old. The beautiful Einstein's relativity theory of space-time and gravity is one of the founding block of modern physics and cosmology in particular. In my talk, I shall discuss why one would like (and actually really need) to design and convey tests of the theory on cosmological scales. Then, I will also present a handful of theories (called Modified Gravity) that aim to rival the ruling of GR at the cosmological distances. Such theories as usually conveyed in order to explain observed accelerated expansion of the Universe without Einstein's cosmological constant. Finally, I will present and discuss some reasonable ways for conveying cosmological test of gravity, discuss why most of them might fail and present some potentially promising avenues for new class of such tests. Concluding with why you might want to stay tuned for future in that field!

Dariusz Prorok

Influence of correlations between yields on the chemical freeze-out temperature (part II)

The statistical (thermal) model is applied for the description of hadron yields measured at central nucleus-nucleus collisions at the top RHIC energy $sqrt{s_{NN}} = 200$ GeV and the LHC energy $sqrt{s_{NN}} = 2.76$ TeV. In contrast to previous analyzes the more general form of the least squares test statistic is used, which takes into account also possible correlations between different species of yields. When light nuclei are included into fits, the chemical freeze-out temperature about 158 MeV is obtained for both energies (156 MeV when correlations are neglected). Without light nuclei the temperature about 160 MeV is determined for LHC and RHIC when correlations are non-zero, whereas for zero correlations the difference in the chemical freeze-out temperatures between RHIC and LHC is 6 MeV.

dr Remigiusz Durka, IFT UWr

The handful of new insights regarding algebra enlargements and spacetime with a gravitational analog of the magnetic monopole.

General Relativity could be generalized in various ways: in particular the first-order formalism of gravity including various algebraic enlargements. Presented class of topics finds interesting applications not only in the construction of the gravity models, establishing the black hole thermodynamics for spacetime supposedly possessing gravitational magnetic monopole, but also in the description of the so-called topological insulators (which are certain real materials studied in condensed matter physics).

Josua Unger

Asymptotic Symmetries and Quantum Groups

In this talk I will discuss the BMS analysis of asymptotically flat spacetime, their algebraic properties and important consequences for black hole physics. The deformation by twisting of the BMS (Hopf-)algebra is presented and motivated in the context of the information loss paradox.

Dariusz Prorok

Influence of correlations between yields on the chemical freeze-out temperature

The statistical (thermal) model is applied for the description of hadron yields measured at central nucleus-nucleus collisions at the top RHIC energy $sqrt{s_{NN}} = 200$ GeV and the LHC energy $sqrt{s_{NN}} = 2.76$ TeV. In contrast to previous analyzes the more general form of the least squares test statistic is used, which takes into account also possible correlations between different species of yields. When light nuclei are included into fits, the chemical freeze-out temperature about 158 MeV is obtained for both energies (156 MeV when correlations are neglected). Without light nuclei the temperature about 160 MeV is determined for LHC and RHIC when correlations are non-zero, whereas for zero correlations the difference in the chemical freeze-out temperatures between RHIC and LHC is 6 MeV.

prof. Anna Szmyrka-Grzebyk, INTiBS PAN, Wrocław

New International System of Units

On 16 November 2018, the 26th General Conference on Weights and Measures (CGPM) approved the new International System of Units, SI. In the system, seven base units are defined by universal constants making it independent of the properties of matter, the place and time of realization of individual units. The four units - kilogram, ampere, kelvin and mole - are presently defined by the following physical constants: the Planck constant h, the elementary charge e, the Boltzmann constant k, the Avogadro constant NA.

prof. Jerzy Kowalski-Glikman

Gravity as a constrained BF theory

In my talk I will present the construction of gravity Lagrangian as a sum of the topological term, the BF theory with (anti-) de Sitter gauge group and a 'constraint' term, explicitly breaking the symmetry down to local Lorentz symmetry. I will then comment on several properties of such defined theory: perturbative expansion around topological vacuum, particle(s) coupling, canonical analysis, and calculation of black hole entropy.

Cezary Juszczak

Solving ordinary and partial differantial equations using neural networks

I will present the method from the paper: 'Artificial Neural Networks for Solving Ordinary and Partial Differential Equations' by Lagaris et al. and some result of its application.

dr hab. Paweł Oświęcimka, prof. IFJ PAN Kraków

Dynamika multifraktali finansowych

Cechą charakterystyczną układów złożonych jest ich wieloskalowa organizacja, którą można zidentyfikować oraz ilościowo opisać w ramach analizy multifraktalnej. Podczas mojego referatu zaprezentuję wyniki analizy multifraktalnej finansowych szeregów czasowych. Pokażę, że własności wieloskalowe przedmiotowych szeregów zależą od rozważanego okresu w czasie i typowo są skorelowane z wydarzeniami historycznymi mającymi odzwierciedlenie w globalnej ekonomii. Analiza własności multifraktalnych może stanowić zatem bardzo użyteczne narzędzie inżynierii finansowej pomocnej w stabilizacji rynku w okresach jego dużej zmienności.

dr hab. Paweł Oświęcimka, IFJ PAN Kraków

Fractals and Agents in Economics: the case of Bitcoin

The concept of fractals and multifractals has gainedvpopularity inrecent years mainly due to the identification of this typevof structures in many, seemingly not related, fields of science such as physics, physiology, economy even linguistics and music. In this presentation I demonstrate the potential of the multifractal methodology which has been applied to characterize complexity of the cryptocurrency, in particular Bitcoin, market. I discuss evolution of the multifractal characteristics towards those identified empirically for all “mature” markets like stocks, commodities or Forex. I also present microscopic agent-based model which is able to reproduce set of "the stylized facts" observed in the financial time series.

Kajetan Niewczas

Electroweak single-pion production off the nucleon: effective implementation in Monte Carlo event generators

Neutrino-induced single-pion production (SPP) provides an important contribution to neutrino-nucleus interaction, ranging from intermediate to high energies. There exist a good number of low-energy models in the literature to describe this process in the region around the Delta resonance. However, their implementation in the Monte Carlo event generators, that are used in accelerator-based neutrino oscillation experiments, is still very limited. I will present a framework exhaustively described in Ref. [J.E. Sobczyk et al., Phys.Rev. D98 (2018) 073001] and its potential to be used for generic and optimized implementations of SPP models. The discussion will be exemplified using the model developed by the Ghent group [R. González-Jiménez et al., Phys.Rev. D95 (2017) 113007] and its implementation in NuWro Monte Carlo generator.

dr Marcin Piątek, Univ. of Szczecin

Quantum and classical Virasoro conformal blocks: advances in the theory, and new applications

I will review my last few years research achievements obtained in collaboration with Franco Ferrari and Artur Pietrykowski. Our research concerns the semiclassical limit of two-dimensional Conformal Field Theory and its applications. I discuss in particular: connections between the semiclassical limit with Yang-Mills theories, quantum integrable systems and moreover applications in black holes physics and holographic interpretation.

Valeriya Mykhaylova

Transport parameters of the quark-gluon plasma: flavour dependence in the quasiparticle model

It is known that the quark-gluon plasma (QGP) is well described in terms of the relativistic hydrodynamics. Therefore, along with its equation of state and phase diagram, we are also interested in the transport properties of the QGP as a fluid. During the talk, I will present recent results for the shear and bulk viscosities, as well as electrical conductivity, obtained from the relaxation time approximation to Boltzmann equation. The calculations are performed within the quasiparticle model, where dynamical quark and gluon masses depend on the running coupling, extracted from the lattice QCD data.

dr Thomas Bahder, ARO Tokyo

Topological Quantum Sensors?

I will review the theory of "conventional" quantum sensors as quantum channels of information between the quantity (classical field) to be sensed and the measurement outcomes. Next, I will briefly describe non-ideal quantum sensors, which perform non-unitary transformations on the input quantum state. The theory of non-ideal quantum sensors is relevant to experiments because the input quantum state may have errors, there may be scattering (decoherence and dispersion) in the quantum channel, and the output state detectors may not be ideal. Next, I will introduce simple 1-qubit and 2-qubit models of a quantum sensor that have an analogy with topological energy band theory. I will suggest that a new class of quantum sensors called "topological quantum sensors" may be realizable. Finally, I will give a detailed example of a topological quantum sensor of magnetic fields based on the dynamical quantum H all effect.

dr Thomas Bahder, ARO Tokyo

Army Research Office (ARO) Overview and Physics Division Objectives

The headquarters of the Army Research Office (ARO) is located in Raleigh Durham, North Carolina, USA. The ARO funds excellent basic research in the sciences. In fact, ARO has funded numerous Nobel laureates over the years. The majority of ARO funding goes to U.S. researchers. However, two years ago, the ARO has started an International Program. I am the Program Manager for the International Program in Physics. My geographical area is the whole world, excluding the continental U.S. (which is covered by other ARO program managers in the U.S.). My goal is to find exceptional basic physics research that is done outside of the continental U.S. My Program is called "Quantum Scale Materials", and it deals with a broad area of quantum physics, including topological physics, quantum sensors, and a variety of other quantum-related physics. My office is in the Roppongi district of Tokyo, Japan. In this talk, I will give an overview of the ARO organization, the International Program, and the Physics Division. I will describe the goals of the ARO International Program in Physics in Asia-Pacific. Finally, I will describe the process of submitting a research proposal to ARO.

dr Aneta Wojnar, Federal University of Espirito Santo, Vitoria

How to use low-mass stars to test theories of gravity

I will show how low mass stars (<0.08 of the solar mass) allow to test theories of gravity. Palatini stars will be the main objects of our discussion.

Michał Marczenko

Effective-Model Perspective on QCD Phenomenology - obrona pracy doktorskiej

Mimo, że teoria opisująca oddziaływania silne, chromodynamika kwantowa (QCD), jest dobrze ugruntowana teoretycznie, istnieje wiele technicznych przeszkód, stanowiących poważne utrudnienie w jej analizie oraz dalszym rozwoju. Istnieje więc potrzeba konstrukcji modeli efektywnych w ujęciu fenomenologicznym, wywodzących się z teorii podstawowej i zawierających jej istotne cechy. Tematem niniejszej rozprawy doktorskiej jest zbadanie właściwości termodynamicznych QCD w ramach różnych modeli efektywnych. Pierwsza część pracy dotyczy wyników QCD na sieci (LQCD) w skończonych temperaturach i zerowej gęstości barionowej, które wykazały rozbieżności między powszechnie stosowanym modelem gazu hadronowego (HRG), ujawniające się na poziomie fluktuacji ładunków zachowanych, w szczególności w sektorze dziwnym. W celu skwantyfikowania tych rozbieżności, model HRG został rozszerzony o ciągłe widmo Hagedorna, którego parametry wyznaczono na podstawie wielkości termodynamicznych LQCD. Otrzymane spektra są zgodne z trendem wyznaczonym przez uwzględnienie niepotwierdzonych barionów dziwnych, wymienionych w bazie Particle Data Group (PDG). To sugeruje, że większość brakującego oddziaływania dla barionów dziwnych znajduje się w sektorze |S|=1. Z kolei widmo uzyskane dla mezonów dziwnych może wskazywać na istnienie nieodkrytych stanów w obszarze średnich mas, niewymienionych jeszcze w bazie PDG. W celu poprawy opisu właściwości oddziałujących hadronów, niezbędne jest wyjście poza uproszczone ujęcie HRG, uwzględniając między innymi efekty rozpadu oraz skończonej szerokości rezonansów. W dalszej części pracy badamy wpływ szerokości rezonansów w ramach modelu macierzy rozpraszania. Model ten, w odróżnieniu od modelu HRG, względnia dynamikę powstawania rezonansów zakodowaną w fizycznym przejściu fazowym. Pozwala to oszacować wpływ rozpraszania K\pi, tj. rezonansów K^*_0(800) i K^*_0(1430), na fluktuacje wypadkowej liczby dziwności. Wyniki wskazują, że uproszczony model oddziaływań HRG systematycznie zawyża wielkości termodynamiczne, a ich wkład oszacowany przy użyciu modelu macierzy rozpraszania rozwiązuje tylko częściowo problem brakującego wkładu do fluktuacji wypadkowej liczby dziwności. Kolejnym omówionym aspektem jest użycie modelu macierzy rozpraszania w modelu blast-wave w celu opisania emisji cząstek w zderzeniach ciężkich jonów. Zbadany został wpływ skończonej szerokości mezonu ρ na rozkład pędu pionów oraz modyfikację widm cząstek powstałych z dwuciałowych rozpadów. W szczególności rozkład niskich pędów poprzecznych pionów powstałych w rozpadzie mezonu ρ jest wyższy o tego otrzymanego w przybliżeniu HRG. Użycie modelu macierzy rozpraszania poprawia opis ilościowy widm pionów w zderzeniach ciężkich jonów w zakresie energii Wielkiego Zderzacza Hadronów w CERN. Porównujemy również model macierzy rozpraszania z przybliżeniem wykluczonej objętości do opisu sił odpychających między oddziałującymi hadronami. Koncentrujemy się na termodynamice systemu πNΔ. Pokazujemy w jaki sposób zwykle stosowany model z wykluczoną objętością prowadzi do przypadkowej zgodności wielkościach termodynamicznych całego układu. Zgodność ta zostaje utracona przy ograniczeniu do konkretnego kanału rozpraszania, gdzie dodatkowa wykluczona objętość między pionami i nukleonami, oprócz siły odpowiedzialnej za formację rezonansu Δ prowadzi do niezgodności z analizą na podstawie fizycznego przejścia fazowego w oparciu o model macierzy rozpraszania. Sugeruje to, że siły odpychające między hadronami nie mogą być opisane pojedynczym parametrem a także są zależne od kanału oddziaływania. Druga część pracy dotyczny efektywnego opisu zimnej oraz gęstej materii oddziałującej silnie. W tym celu wykorzystany jest hybrydowy model kwarkowo-mezonowo-nukleonowy (QMN). Dynamika chiralna opisana jest w nim w ramach liniowego modelu sigma, podczas gdy uwięzienie kwarków otrzymane jest przy pomocy zależnej od ośrodka modyfikacji funkcji rozkładu Fermiego-Diraca, gdzie wprowadza się dodatkowe pole skalarne. Charakterystyczną cechą modelu jest fakt, że przy rosnącej gęstości, symetria chiralna zostaje przywrócana jeszcze w fazie hadronowej, przed spontanicznym uwolnieniem kwarków. W pracy rozważona jest termodynamika układów dwuzapachowych w przybliżeniu pola średniego. Dla niskich temperatur oraz wysokich gęstości model przewiduje chiralne przejście fazowe pierwszego lub drugiego rzędu, lub gładkie przejście typu crossover, w zależności od wartości oczekiwanej pola skalarnego. Spontaniczne uwolnienie kwarków jest natomiast przejściem pierwszego rzędu. Badamy również równanie stanu w modelu QMN w warunkach gwiazdy neutronowej. W tym celu model jest uogólniony do przypadku dowolnej asymetrii izospinowej. Wyznaczone są zależności między masą a promieniem gwiazdy, poprzez narzucenie warunków zgodności z niedawno odkrytym pulsarem PSR~J0348+0432, a także ograniczeniami na zwartość gwiazdy z pomiaru GW170817. Uwzględniony jest również próg dla bezpośredniego procesu URCA, dla którego wyprowadzone jest nowe oszacowanie. Biorąc pod uwagę ograniczenia, model przewiduje, że na diagramie fazowym materii symetrycznej, punkt krytyczny przejścia chiralnego znajduje się w obszarze niskich temperatur lub znika całkowicie. Na koniec omówniona jest charakterystyka fluktuacji liczby barionowej na granicach faz chiralnego przejścia fazowego oraz spontnicznego uwolnienia kwarków w hybrydowym modelu QMN. Badany jest wpływ uwięzienia kwarków na kumulanty wyższych rzędów fluktuacji liczby barionowej. Otrzymane kumulanty wykazują znaczne wzmocnienie wokół chiralnego przejścia fazowego, podczas gdy nie są wrażliwe na hadronowo-kwarkowe przejście fazowe.

Marzieh Bahmani

Computing in physics

In this talk I will discuss the fundamental concepts of Physics computing by addressing two specific aspects of scientific computing: tools and techniques for scientific software and Data Analysis. Tools and techniques dedicated to modern techniques for software design, better understanding and improving the existing software and Data Analysis aspect will be an introduction to data analysis techniques and Monte Carlo method.

Dipl.-Phys. Niels-Uwe Bastian, IFT UWr

publiczna obrona rozprawy doktorskiej

tytuł rozprawy doktorskiej: Density functional theory for a unified description of quark-hadron matter and applications in heavy-ion collisions and astrophysics

prof. Anthony Ladd, University of Florida

Dissolution at the pore scale: comparing simulations and experiments

Flow and transport in porous media are usually modeled at the Darcy scale, where the system is comprised of representative elementary volumes (REV's) described by average properties such as porosity, permeability, dispersion coefficients, and reactive surface area. However, if there is rapid dissolution, such as when brine pressurized with CO2encounters calcite, the validity of the averaging process is called into doubt by the strong gradients in concentration within a single REV. Pore-scale modeling overcomes many of the limitations of Darcy-scale models, albeit at a much greater computational cost. Here we describe some preliminary results of comparisons of numerical simulations of the dissolution of a soluble cylinder with microfluidic experiments, and with approximate calculations from conformal mapping. The numerical simulations use a finite-volume discretization, with an unstructured mesh that conforms to the shape of the dissolving object. By exploiting the intrinsic separation of time scales between transport and dissolution, precise simulations can be carried out with limited computational resources. We used the OpenFOAM toolkit with customized libraries to support mesh motion and relaxation around the dissolving object. Simulations take a few hours, in comparison with 1 month for the laboratory experiments.

dr hab. Bernard Jancewicz

Fala elektromagnetyczna w modelu Friedmana

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prof. Helmut Satz, Univ. Bielefeld

Novel critical behaviour: the statistical mechanics of bird swarms

In the past twenty years, a new field of statistical physics has emerged, the study of the self-organized behaviour of animal swarms. It was started in 1995 by a seminal paper of T. Vicsek and collaborators in Budapest and has since then been considerably extended. In 2008, extensive empirical data on starling flocks were provided by the STARFLAG project, carried out at the University of Rome, with G. Parisi as coordinator. These data were well accounted for by extended versions of Vicsek model, which is based on a generalized sin system, with local nearest neighbour interactions leading to spontaneous symmetry breaking and collective global behaviour.

dr Remigiusz Durka

Nuts approach to the Taub-NUT space-time (Pokręcone podejście do czasoprzestrzeni Tauba-NUT)

I offer new approach to the subject of Taub-NUT space-time supposedly possessing gravitational analog of the magnetic monopole. Starting from realizing that the source of many inconsistencies lies in neglecting the effects of the wire singularities present in that solution, I am able to explain existence of the NUT parameter by the means of quite peculiar rotation. Among many things, this leads to the consistent description of the black hole thermodynamics for the Lorentzian Taub-NUT spacetime with the essential contribution to the angular momentum and the total entropy.

Cezary Juszczak

Supervised deep learning in high energy phenomenology

I will present results of the paper arXiv:1905.06047 [hep-ph]

prof. dr hab. Armen Sedrakian, IFT UWr

Exploring phases of dense matter with astrophysics of compact stars

In this talk, I will focus on the behavior of matter at high densities in compact stars and the challenges that emerged in recent years in the nuclear physics and astrophysics of these objects. The possibility that new particles appear in the dense matter will be discussed. In particular, I will discuss the phase transition from baryonic to deconfined quark matter and its consequences for compact star astrophysics. I will show that a strong first-order phase transition among the phases of dense quark matter can lead to triplet configurations of compact stars, i.e., three stars with the same masses but different radii. Finally, I will discuss the implications of the recent detection of gravitational waves from a collision of two neutron stars.

Piotr Brzeski

Nowe wyniki w modelu perkolacji hipersfer

Podczas seminarium zostaną zaprezentowane wyniki najnowszych symulacji dla modelu perkolacji dyskretnej hipersfer na D-wymiarowej sieci hiperkubicznej.

prof. Jerzy Lukierski

Celebration of prof. Jerzy Lukierski birthday

Our next group seminar on May 21st is going to be devoted to the celebration of prof. Jerzy Lukierski birthday. We are offering short speeches, a bit of wine, some sweets, and a good deal of friendly chats. Everybody is cordially invited.

Krzysztof Graczyk

Statistical methods in approaching solution of the proton radius puzzle

I will shortly review recent approach to extraction of the proton radius. Special attention will be focused on the statistical methods.

Dipl.-Phys. Niels-Uwe Bastian, IFT UWr

Phenomenology of the QCD phase transition

Even half a century after the introduction of the quark model, their behaviour is barely understood. Ab initio calculations of QCD, the theory of strongly interacting matter, are only accessible at vanishing chemical potentials. The rest of the QCD phase diagram is under heavy debate, which is the topic of astrophysics and modern heavy-ion collision experiments. In particular, the possible appearance of a phase transition of first-order from ordinary nuclear matter to the so-called quark-gluon plasma is a matter of many speculations. In the first part of my presentation, I will present our research on the detectability of such phase transitions in astrophysics. It turns out, that the mass-radius measurement of neutron stars, the gravitational wave signal of binary neutron star mergers as well as the neutrino signal of supernova explosions might produce detectable signals in case of a first-order phase transition. The second part will address the formulation of thermodynamics of strongly-interacting matter. I will present two newly developed formalisms which are together capable to describe even complex interactions as confinement and treat hadrons as bound states of quarks. These features lead me to the final goal to formulate a unified description of the entire quark-hadron phase diagram.

Jan Sobczyk

Weak pion production ANL and BNL data - neverending story

I will present a few (relatively) recent studies on the 40 years old weak pion production data on deuteron target.

dr Kazuki Sakurai, UW

A fresh look at the gauge coupling unification and proton decay

In this talk I will review the success of the gauge coupling unification in the minimal supersymmetric (SUSY) extension of the Standard Model. We will see that in order to quantitatively address the coupling unification, one must take into account the effect of mass splitting both in SUSY (m ~ TeV) and Grand Unified Theory (GUT) (m ~ 10^16 GeV) sectors, known as threshold corrections. I will develop convenient mathematical formulae to ensure the coupling unification, and use them to predict the proton lifetime to constrain the low energy SUSY spectra in a given GUT model. We will see there is an interesting complementarity between the proton decay experiments and the direct SUSY searches at the LHC.

mgr Lennart Brocki

BMS Group at Spatial Infinity

In this talk I present a recent publication by Henneaux and Troessaert in which they propose new boundary conditions for asymptotically flat spacetimes at spatial infinity and find that the conserved charges close according to the BMS algebra. Their analysis relies on the Hamiltonian formalism of general relativity and is an extension of the work done by Regge and Teitelboim in 1974, which will therefore also be summarized, and mainly differs in the choice of parity conditions. For a more complete understanding the talk will also cover some basics about the BMS Group.

Tomasz Bonus

Towards a phenomenological 2p2h model

Presentation of results achieved by implementing MEC scaling factor which depends on kinematic variables of the event. Main point is to discuss improvement of chosen quality metrics and way of diminishing them even further avoiding unphysical results.

mgr Michał Marczenko, IFT UWr

Modeling Cold and Dense QCD Matter

One of the most significant aspects of QCD thermodynamics is understanding how the transition from hadrons to their constituents—quarks and gluons—relates to the underlying deconfinement and chiral dynamics. This is of major relevance for heavy-ion collisions, as well as in the study of cold and dense systems, such as compact stars. In this talk, I present a description of QCD matter based on the effective hybrid quark-meson-nucleon model for QCD phase transitions at low temperatures and finite baryon densities. The structure of the net-baryon number fluctuations along with its higher order cumulants is discussed as possible probes for the phase transitions. I also discuss the implications of the chiral symmetry restoration on the mass-radius relation for compact stars obtained in accordance with the modern astrophysical constraints.

mgr Lennart Brocki

BMS Group at Spatial Infinity

In this talk I present a recent publication by Henneaux and Troessaert in which they propose new boundary conditions for asymptotically flat spacetimes at spatial infinity and find that the conserved charges close according to the BMS algebra. Their analysis relies on the Hamiltonian formalism of general relativity and is an extension of the work done by Regge and Teitelboim in 1974, which will therefore also be summarized, and mainly differs in the choice of parity conditions. For a more complete understanding the talk will also cover some basics about the BMS Group.

Prof. Peter Braun-⁠Munzinger ,GSI Darmstadt

Decoding the QCD phase structure with relativistic nuclear collisions

In this talk we demonstrate that the phase structure of strongly interacting matter can be decoded via analysis of particle production in high energy nuclear collisions. This is achieved by making use of the observed thermalization pattern of particle abundances within the framework of the statistical hadronization approach at various collision energies. The thermalization holds not only for hadronic constituents composed of light quarks but also for light, loosely bound nuclei. The observed energy dependence of the production yields and fluctuations of different particle species contains characteristic features which are used to determine the temperature and baryo-chemical potential of the matter produced. The above observations imply quark-hadron duality at the QCD phase boundary and establish the first experimental delineation of the location of the phase change in strongly interacting matter. New experimental opportunities for relativistic nuclear collisions are pointed out for the near and longer term future.

Prof. Johanna Stachel, Heidelber Univ.

Charmonia as Probe of Deconfinement -⁠ Recent Results and Perspectives

Charmonia are hadrons composed of a charm quark and its anti-particle. Their production mechanism in relativistic nuclear collisions and its connection to a quark-gluon plasma (QGP) formed there has been a key topic for more than 30 years. In this talk we will demonstrate how recent results from the Large Hadron Collider have shed new light on the topic: the presence of a QGP does not reduce but actually enhance their production at collisers since charm quarks in the fireball are deconfined. This implies that the production rate of charmonia scales quadratically with the number of charm quarks, thereby providing a fingerprint for deconfinement and the position of the QCD phase boundary. The underlying physics is well described in the Statistical Hadronization Model for Charm (SHMC) which was proposed nearly 20 years ago. We will present the current experimental situation and the comparison to the most recent SHMC predictions. The fundamental question whether there exist colorless bound states inside the QGP is related to the experimentally challenging measurements of excited-state populations of charmonia which will be studied with precision with the upgraded ALICE apparatus at the LHC in the coming years.

Beata Kowal

Studying of polarization observables in neutrino-nucleon scattering

I will present results from the papers in which I've investigated polarization observables in single pion production in neutrino-nucleon scattering.

mgr Aleksander Kozak

Palatini frames in scalar-tensor theories of gravity

Conformal transformations play an important role in the scalar-tensor theories of gravity, as they allow one to carry out calculations in a more convenient frame, simplifying the field equations. In the Palatini approach, however, the metric structure of space-time is decoupled from its affine structure, so that a transformation of the metric does not entail a corresponding change in the connection. One needs to define independent transformation for the connection, reducing to the standard formula in case the connection is Levi-Civita with respect to the metric. In my presentation, I shall introduce a scalar-tensor theory taking into account such transformation and discuss properties of the solution to the field equation for the connection. I will also introduce invariant quantities, whose functional form remains the same in every conformal frame, and show how they can be applied to analysis of possible equivalence between F(R) and scalar-tensor theories of gravity in the Palatini approach. The main part of the talk will be preceded by a short introduction to metric scalar-tensor theories and conformal transformations.

dr Artur Barasiński

Streszczenie wyników badań nad teorią korelacji kwantowych dla układów dwu - i trój - kuditowych

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prof. dr hab. Zbigniew Koza, IFT UWr

Percolation of k-mers on the square lattice

In the first part of the seminar I will summarize some basic methods and results obtained so far for percolation. In the second part I will present our recent achievements on the percolation of k-mers on the square lattice and its relation to the Random Sequential Adsorption.

dr Mateusz Denys, UW

An application of space-time spectral analysis for seismic-wave detection in Virgo interferometer

Virgo is a European detector of gravitational waves located near Pisa, Italy. In order to detect gravitational waves Virgo must be extremely sensitive and well isolated from the external perturbances. However, it cannot be isolated from local changes of gravitational field, resulted, for instance, from mass movements under the surface of the Earth. This part of the gravitational-field changes is called Newtonian noise and, fortunately, it can be calculated using measurements of seismic noise in the vicinity of the Virgo detector. I am going to present a method for detection of seismic waves that I proposed during my internship in Virgo Collaboration. The method uses data from the seismic detectors in the west-end Virgo building and is based on the mixed space-time spectral (Fourier) analysis. It can be applied to Newtonian noise calculation in Virgo and to a broad range of other similar problems.

Prof. Eiji Nakano (Kochi University, Japan)

Bose polarons in the trap

Polaron originaly means the conducting electron dressed by phonon cloud in a dielectric crystal, described as a quasiparticle with a medium dependent effective mass. Recently a cold-atomic many body system mimics the polaron, where an impurity atom immersed in atomic BEC is dressed by Bogoliubov phonon cloud to be a 'Bose polaron'. The Bose polaron has been observed in some experiments in a very controlled way: dimensionality, interaction between impurity and BEC atoms, and property of BEC can be designed almost at will. Theoretical works so far entirely assumed uniform systems, although the experiments were done in traps.The local density approximation is not an adequate tool for detailed description of polaron structure, because the impurity itself causes inhomogeneity. So, we directly calculate properties of Bose polarons in trap potentials, taking care of the angular momentum conservation, instead of the momentum conservation in uniform systems.

dr Tomasz Pawłowski

Introduction to Loop Quantum Cosmology

dr hab. Maciej Matyka, IFT

Fluid dynamics in porous media and beyond

The seminar will be mostly about our research on fluid dynamics, tortuosity and velocity distribution function in porous media. Our recent results on the scaling of the velocity histograms in random and fractal media will be presented. The most recent results from the flow through fractal media (together with MSc student W. Saramak) will be shown. I will also talk about perspectives and other ongoing projects.

prof. dr hab. Jerzy Lukierski, IFT Uwr

New Approach to Colour Triplets of Quarks, Graded Extension of Lorentz Symmetries and Algebraic Confinement

The modification of standard description of colour quarks triplets is proposed. We introduce 12-component colour quark multiplets, with Z_3 symmetry playing important algebraic role in quarks confinement. In such framework SU(3) colour symmetry is entangled with Z_3-graded extension of Lorentz symmetry. The extended Lorentz covariance leads to the presence of 12 colour quark multiplets which can be linked with the appearence of all observed internal symmetries of quarks. This talk is based on my recent paper with Richard Kerner (arXiv:1901.10936)

Christopher Thorpe (Lancaster University)

Hyperon Production in the NuWro Monte Carlo Generator

Upcoming neutrino detectors such as SBND will be exposed to very intense neutrino beams and are predicted to observe thousands of hyperon production events versus the existing dataset of fewer than 100. These processes are of interest as they may be used to identify wrong sign contamination in neutrino beams, test the quark flavour model and search for time reversal violating interactions. These processes have been modelled in the NuWro MC event generator with the ability to include flavour and time reversal symmetry breaking modifications. Interactions between the hyperons and nuclear material have also been implemented. Some samples of the outputs from the generator will be presented to examine the effect of the changes to the model on various observables and to look at the severity of the nuclear effects.

prof. dr hab. Adam Lipowski, UAM

Ising model on (un-⁠)directed random graphs

First, we recall some basic percolative properties of random undirected graphs and discuss the behaviour of the Ising model on such graphs. In particular, we emphasize that emergence of finite temperature ferromagnetism coincides with the percolation transition and a similar behaviour occours on some diluted cartesian lattices. Then, we examine Ising models on directed graphs. Such models do not obey the detailed balance but on some regular lattices they behave similarly to their equilibrium counterparts. Numerical simulations show that for directed random graphs to support finite temperature ferromagnetism the spanning cluster must be sufficiently dense. Similar behaviour appears in some other models with agreement dynamics.

Mahboubeh Shahrbaf (University of Teheran, Iran)

Using a variational method to study nuclear matter, hyper nuclear matter and neutron stars

We investigate the equation of state of nuclear matter, hyper nuclear matter and compact stars within our variational method. Chemical potentials of nucleons in asymmetric nuclear matter are calculated in a completely self-consistent manner, using the lowest order constrained variational (LOCV) method. Employing different nucleon–nucleon potentials, threshold density of free hyperons formation and the maximum mass of hypernuclear star are determined. Furthermore, the particles fraction in beta stable and charge neutral matter is calculated as well. The effects of three-body force (TBF) on the onset of hyperons, particle composition and maximum mass of the star are discussed. On the basis of this method which is reformulated by using two-body central potentials for Λ-N and Λ-Λ interaction that were determined so as to reproduce the experimental data on single- and double-Λ hypernuclei, the equation of state of hyper nuclear matter is found for the first time in this method. Calculation of correlation functions for N-Y and Y-Y interaction for each JLSTMT-channel is done for the first time as well.

Krzysztof Graczyk

Rozwiązywanie równań różniczkowych przy pomocy sieci neuronowych

Sieci neuronowe używane są przede wszystkim w problemach klasyfikacyjnych oraz regresji. W ostatnim okresie sztuczne sieci neuronowe stały się popularnym narzędziem wykorzystywanym w wielu dziedzinach życia. Ich zastosowania w fizyce są bardzo szerokie: od fizyki ciała stałego do fizyki cząstek elementarnych, od fizyki doświadczalnej do fizyki matematycznej. Metody sztucznej inteligencji są choćby jednym z narzędzi wykorzystywanym w klasyfikacji mierzonych zdarzeń w detektorach cząstek elementarnych. Metod tzw. uczenia maszynowego używa się również do rekonstrukcji funkcji falowych układów wielu ciał. Ciekawym zastosowaniem wydaję się użycie metod uczenia maszynowego do rozwiązywania numerycznego zwykłych i cząstkowych równań różniczkowych. Podczas seminarium omówię kilka zastosowań tej metody w rozwiązywaniu problemów fizycznych.

dr Pok Man Lo, IFT UWr

Scattering Theory Approach to the Thermodynamics of Hadrons

In this talk I shall review how the S-matrix formalism can be applied to study the thermal properties of interacting hadrons. The central idea of this approach is to compute an effective density of state from the scattering phase shifts. As the phase shifts encode a wealth of information on the hadronic interactions, e.g. the resonance widths and masses, the method can robustly handle the case of a broad resonance or a purely repulsive channel. As an application I will present an analysis on the proton yield from the heavy ion collision experiments at the LHC. I will discuss how the inconsistency between theory and experiment, the so-called proton puzzle, may be resolved by considering some essential features of the empirical baryon spectrum. These features are also crucial for understanding the Lattice results on thermal QCD, such as the baryon electric charge correlation. Lastly, I will report on some recent progress in analyzing the coupled-channel system of hyperons and the inclusion of $N>2$-body scatterings.

Diana Alvear Terrero (IFT)

Modelling anisotropic magnetised White Dwarfs with $gamma$ metric

Magnetic fields introduce an anisotropy in compact stars' equations of state by splitting the pressure into two components, one parallel and the other perpendicular to the magnetic field. This suggests the necessity of using structure equations accounting for the axial symmetry of the magnetised system. We consider an axially symmetric metric in spherical coordinates, the $gamma$-metric, and construct a system of equations to describe the structure of spheroidal compact objects. In this way, we connect the geometrical parameter $gamma$ linked to the spheroid's radii, with the source of the anisotropy. So, the model relates the shape of the compact object to the physics thatdetermines the properties of the composing matter. To illustrate how our structure equations work, we obtain the mass-radii solutions for magnetised White Dwarfs.

Diana Alvear Terrero

Effects of magnetic fields and slow rotation in white dwarfs

We use Hartle’s formalism to study the effects of rotation in the structure of magnetised white dwarfs within the framework of general relativity. We describe the inner matter by means of an equation of state for electrons under the action of a constant magnetic field, which introduces an anisotropy in the pressures. Solutions correspond to typical densities of white dwarfs and values of magnetic field below 10^13G considering perpendicular and parallel pressures independently, as if associated to two different equations of state.

dr Sławomir Drobczyński, PWr

Optical tweezers. The Nobel Prize in Physics 2018

The theory of light pressure was introduced by James Clerk Maxwell in 1873. Fact that light might exert optical force was confirmed experimentally in 1900 by the Russian physicist Piotr Lebedev. A significant breakthrough in the study of optical forces occurred only after the appearance of lasers. A pioneer of experiments with a highly focused laser beam acting on dielectric microobjects was Arthur Ashkin. In 1986, he published his work , in which he described the first successful attempt of optical trapping using a single laser beam. Optical trapping results from the small forces associated with the electric field gradient acting on the dielectric microparticles located in the focused laser beam. Laser beams with powers of hundreds of milliwatts are capable of exerting forces of piconewton orders. Optical trapping technique applicable in many fields of science. Within a few years from the publication of the work by Ashkin, many laboratories around the world have begun many interesting studies. Optical tweezers can be used to manipulate non-living and living matter. It soon turned out that the optical trapping technology allows carrying out previously unattainable tests on the microscale. The possibility of a non-invasive and sterile hold of micro-objects, e.g. cells or biomolecules, has found particular application in biology and medicine.

Josua Unger

kappa-deformed BMS symmetry

In this talk I will give an overview about the use of Hopf algebras in fundamental physics. I will present and discuss the BMS algebra. Furthermore this BMS algebra will be deformed to a Hopf algebra that contains the kappa Poincare algebra.

dr hab. Brynmore Haskell (CAMK Warsaw)

Probing fundamental physics with multi-messenger observations of neutron stars

Neutron stars are an extraordinary laboratory for probing fundamental physics in extreme conditions that cannot be reproduced in terrestrial experiments. Not only are the core of these stars denser than atomic nuclei, but their thermal energies are small compared to the Fermi energies of their degenerate constituents. In these conditions it is favourable for Fermions (mostly, but not only, neutrons in most of the star) to pair and become superfluid. Superfluidity adds a new dimension to the problem, as components can now flow relative to each other and additional degrees of freedom become available. Strikingly, these microphysical properties can have large scale, astrophysical consequences. Superfluidity is thought to be at the heart of glitches, sudden spin-ups observed in radio pulsars, and is likely to play an important role in the physics of gravitational wave emission. In this talk I will present recent advances in theoretical modelling of neutron star superfluids, and discuss observational tests that can constrain the models, in particular observations of radio pulsars and gravitational wave observations with Advanced LIGO and Virgo.

Valeriya Mykhaylova (IFT)

Shear viscosity of the QGP from the relaxation time approximation within the quasiparticle model

It is known that the quark-gluon plasma is well described in terms of perfect fluid dynamics [1]. Besides, it is a common fact that there is nothing perfect in the world (although one should try - LT :-) ). Therefore, one needs to include dissipative processes, which are described by transport coefficients, into the QGP dynamics. I will present the shear viscosity obtained from the relaxation time approximation of the Boltzmann equation. The calculations are performed within the quasiparticle model, where dynamical quark and gluon masses depend on the lattice data [2]. [1] E. Shuryak, Prog. Part. Nucl. Phys. 53 (2004) [2] S. Borsanyi et al., Phys. Lett. B 370 (2014) 99-104

Valeriya Mykhaylova

Shear viscosity of the QGP from the relaxation time approximation within the quasiparticle model

There are experimental evidences that the quark-gluon plasma (QGP) produced in the heavy-ion collisions, is well described in terms of ideal hydrodynamics [1]. However, for more realistic interpretation, the dissipative viscous processes should be taken into account. One of the parameters describing the dissipation of the energy is a shear viscosity, which I have obtained using the relaxation time approximation to the Boltzmann equation. The calculations are performed within the quasiparticle model, in which quarks and gluons have changing (dynamical) masses obtained from the lattice QCD data [2]. [1] E. Shuryak, Prog. Part. Nucl. Phys. 53 (2004) [2] S. Borsanyi et al., Phys. Lett. B 370 (2014) 99-104

prof. Abhijit Bhattacharyya, University of Calcutta

The Statistical Mechanics of Particle Physics

The strongly interacting matter undergoes a phase transition at high temperature and/or density. Such conditions have existed in the early universe. They may also exist inside neutron stars. I will discuss how such a situation can be created in the laboratory and also different properties of hot and dense strongly interacting matter.

Michał Szymański (IFT)

NJL model in strong magnetic field

Strong magnetic fields are expected to be present in non-central heavy ion collisions and in the interior of compact stars. Lattice QCD simulations show that deconfinement and chiral phase transition are affected by the presence of magnetic field. I will discuss properties of the latter using the Nambu-Jona-Lasinio model. Effect of th lowest Landau level will be also examined.

dr hab. Jarosław Korbicz (CFT Warszawa)

Aspekty struktur rozgłoszeniwych w teorii dekoherencji

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Łukasz Juchnowski (IFT)

CANCELLED Pion-gluon interaction through Boltzmann equation

CANCELLED We study the particle production in the early stage of the ultrarelativistic heavy-ion collisions. To this end the Boltzmann kinetic equations for gluons and pions with elastic rescattering are considered together with a simple model for the parton-hadron conversion process (hadronisation). It is shown that the overpopolation of the gluon phase space in the initial state leads to an intermediate stage of Bose enhancement in the low momentum gluon sector that is reflected in the final distribution function of pions, which is very similar to the experimental finding of a low-momentum pion enhancement in the ALICE experiment at CERN LHC. In this talk I will present state of the project and difficulties we are facing.

Alexis Nikolakopoulos

Neutrino energy reconstruction in accelerator-based neutrino-nucleus scattering experiments

No abstract provided

dr Artur Barasiński, Palacky University

Role of multipartite entanglement in quantum teleportation

Quantum teleportation is considered as one of the major protocols in quantum information science. By exploiting the physical resource of entanglement, quantum teleportation has played a prominent role in the development of quantum information theory and represents a fundamental ingredient to the progress of many quantum technologies. Although quantum teleportation is a typically bipar- tite process, it can be extended to multipartite quantum protocols. An important example of such extension is known as the controlled quantum teleportation which forms a backbone of quantum teleportation network, a prelude for a genuine quantum Internet. It is commonly believed that con- trolled teleportation (and quantum teleportation network) is a clear manifestation of multipartite entanglement and both protocols involve pre-sharing a genuine multipartite entangled resource. In my presentation, I will discuss the role of multipartite entanglement in controlled quantum telepor- tation. In particular, I shall present a counterintuitive result of successful controlled teleportation performed without multipartite entanglement what disproves the current misconception.

Mateusz Cierniak (IFT)

Dyson–Schwinger equations in astrophysics

We study the properties of dense, strongly interacting matter using the Dyson-Schwinger equation (DSE) formalism. Within this formalism, by using particular sets of truncations, one can self consistently derive quark properties in–medium. No first principle calculations of QCD are able to provide reliable results for such conditions. The effective models used instead, most notably the Nambu–Jona-Lasino and tdBag models can be understood as limiting cases of the DSE. Furthermore, the formalism provides a straightforward method for extending the derived models to finite temperature and isospin asymmetry, making them useful for studies of astrophysical phenomena such as core–collapse supernovas, neutron star mergers and in general to derive neutron star properties. We will focus on the current state of–the–art in DSE studies of these phenomena.

Aleksander Kozak

Palatini frames in scalar-tensor theories

Conformal transformations play an important role in the scalar-tensor theories of gravity, as they allow one to carry out calculations in a more convenient frame, simplifying the field equations. In the Palatini approach, however, the metric structure of space-time is decoupled from its affine structure, so that a transformation of the metric tensor does not entail a corresponding change in the linear connection. One needs to define independent transformation for the connection, reducing to the standard formula in case the connection is Levi-Civita with respect to the metric. In my presentation, I shall present a scalar-tensor theory taking into account such transformation, called 'generalized almost-geodesic mapping', and discuss properties of the solution to the field equation for the connection. The theory will be analysed in both the Einstein and the Jordan frame. I will also introduce invariant quantities, whose functional form remains unchanged irrespective of the conformal frame, and show how they can be applied to analysis of possible equivalence between F(R) and scalar-tensor theories of gravity in the Palatini formalism.

prof. dr hab. Edward Malec, UJ

Gravitation and accretion of matter.

The energy efficiency in accretion processes onto black holes might exceed tenfold (and even more) the efficiency of thermonuclear fusion. Thus it is not suprising that brightest objects in the Universe are powered by accretion of matter onto black holes. The physical description of such systems must refer to Einstei equations with selfgravity of infalling fluids included, and in the first step (selfconsistent) equilibria solutions have to be found. I shall report recent results, obtained in Krakow, on finding stationary configurations that describe rotating fluid disks around spinless or spinning black holes. One of important ingredients is the discovery of new rotation laws; they include, in particular, generalization of the familiar Keplerian rotation. Interestingly, the general-relativistic Keplerian rotation seems to fit to the description of a phase of evolution of the black hole and a torus, that are produced in the coalescence of two neutron stars, and that might be associated with the recent detection (GW170817) of gravitational waves and gamma rays bursts.

Remigiusz Durka

Różne aspekty teorii grawitacji

Postaram się pobieżnie zaprezentować swoją tematykę badawczą dotyczącą grawitacji. Część tematów dotyczyć będzie zagadnień formalnych (np. konstrukcji modeli grawitacyjnych wynikających z różnych uogólnień), ale nie zabraknie też bardziej obliczeniowych aspektów (np. algebry rezonansowe, obliczenia skalara Kretschmanna i innych niezmienników). Dość ciekawą grupą będą też zagadnienia na styku teorii grawitacji i elektromagnetyzmu (czasoprzestrzeń z grawitacyjnym analogiem monopolu magnetycznego oraz opis topologicznych izolatorów przy użyciu maszynerii teorii grawitacji w 2+1 wymiarach).

Piotr Kopszak

Positive operators and entanglement detection

Quantum entanglement is one of the most important phenomenon in quantum physics. It is interesting from the conceptual point of view, as well as very important in many applications. There are several methods of detecting and classifying entanglement. In my presentation I will concentrate on special observables, namely entanglement witnesses. I will present connection between them and linear operators that are positive, but not completely positive. and recent advances in describing new classes of such operators.

dr Tomasz Pawłowski, UW

Loop Quantum Cosmology: from polymer quantization to Early Universe dynamics

Loop Quantum Cosmology is an application of a nonstandard (that is based on a representation different from Schroedinger one) quantization procedure applied to quantize the spacetime itself in context of (simple) cosmological models of Universe. I will present a very brief outline of the theory and its main results. Further I will discuss some of its advantages, caveats and challenges following from its reliance on the nonstandard (the so called polymeric) quantization, and present recent results following from exploration of these aspects of the formalism.

Lennart Brocki

Functional Schrödinger Picture and Wheeler-DeWitt Equation

In quantum field theory one usually employs the Fock basis to represent the eigenstates of the Hamiltonian, but there exists, in full analogy to quantum mechanics, a functional Schrödinger picture in field theories. I will give a brief overview of this formalism and also present some notions of canonical quantum gravity, which is one of its main applications. In this context I will speak about the quantization of constrained systems and the Wheeler-DeWitt equation.

Niels-Uwe Bastian (IFT)

(First steps) towards a unified quark-hadron matter equation of state

We consider a cluster expansion for strongly correlated quark matter where the clusters are baryons with spectral properties that are described within the generalized Beth-Uhlenbeck approach by a medium dependent phase shift. We employ a simple ansatz for the phase shift which fulfils the Levinson theorem by describing an on-shell bound state with an effective mass and models the continuum by an anti-bound state located at the mass of the three quark threshold. The quark and baryon interactions are accounted for by the coupling to scalar and vector meson mean fields modelled by density functionals. At increasing density and temperature, due to the different medium dependence of quark and baryon masses, the Mott dissociation of baryons occurs and the nuclear clusters contributions to the thermodynamics vanish. It is demonstrated on this simple example that this unified approach to quark-nuclear matter is capable of describing crossover as well as first order phase transition behaviour in the phase diagram with a critical endpoint.

dr hab. Jarosław Korbicz (CFT Warszawa)

Techniczne ( i nie tylko) uzupełnienie referatu na seminarium instutytowym

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dr hab. Jarosław Korbicz, CFT PAN

Spectrum Broadcast Structures And Quantum Origins Of Objectivity

I will present an overview of a recently introduced tool for analysis of open quantum systems and decoherence processes called Spectrum Broadcast Structures (SBS). These are multipartite quantum states, originating from the quantum Darwinism idea of W. H. Zurek, and of a surprisingly simple form but with a surprisingly far reaching and potentially fundamental importance. I will first discuss SBS on an a general level and present their intimate connection to the problem of objectivity in quantum mechanics, as one of the aspects of the quantum-to-classical transition. Then, I will overview appearances of SBS in well known quantum open dynamics models. Finally, I will comeback to general considerations and will discuss how SBS can help better understand the measurement problem in quantum mechanics.

David Blaschke (IFT, UWr), Alexandra Friesen (JINR Dubna).

Quark Pauli blocking in hadronic matter

We show that the Phi-derivable formulation of the cluster virial expansion for quark matter contains the quark Pauli blocking effect in the lowest order expansion with respect to the backreaction of hadrons on the quark dynamics. We discuss this effect for the pion gas and for nuclear matter within a nonrelativistic potential model and estimate its enhancement by partial chiral symmetry restoration in dense matter.

Przemysław Socha

Relacyjne i nierelacyjne bazy i modele danych - porównanie na przykładzie bazy grafowej.

Podczas pierwszego wystąpienia przedstawię wyniki z mojej pracy magisterskiej, która dotyczyła porównania modelu relacyjnego i grafowego w kontekście wydajności tworzonej bazy danych. Dodatkowo opowiem o pozostałych popularnych nierelacyjnych systemach przetwarzania danych.

mgr Przemysław Socha

Relacyjne i nierelacyjne bazy i modele danych - porównanie na przykładzie bazy grafowej

Podczas pierwszego wystąpienia przedstawię wyniki z mojej pracy magisterskiej, która dotyczyła porównania modelu relacyjnego i grafowego w kontekście wydajności tworzonej bazy danych. Dodatkowo opowiem o pozostałych popularnych nierelacyjnych systemach przetwarzania danych.

mgr Przemysław Socha

Relacyjne i nierelacyjne bazy i modele danych - porównanie na przykładzie bazy grafowej

Podczas pierwszego wystąpienia przedstawię wyniki z mojej pracy magisterskiej, która dotyczyła porównania modelu relacyjnego i grafowego w kontekście wydajności tworzonej bazy danych. Dodatkowo opowiem o pozostałych popularnych nierelacyjnych systemach przetwarzania danych.

prof. dr Marlene Nahrgang, IMT Atlantique, Nantes

Super hot and extremely dense - is there a critical point for the strong interaction?

Performing heavy-ion collisions at ultra-relativistic energies gives us access to new states of matter, like the quark-gluon plasma. When the hot and dense fireball created in these experiments expands and cools, the system undergoes a phase transition to hadronic degrees of freedom, which are measured in the detectors. A central question of research in this field is whether a critical point for strongly interacting matter exists. In this talk, I will review the current status of and future directions in the search for this critical point.

Maciej Lewicki (IFT)

NA61/SHINE news - preliminary signatures of deconfinement and clustering effects in the hot dense hadronic matter

NA61/SHINE is a fixed target experiment at the CERN Super Proton Synchrotron. The main goals of the experiment are to discover the critical point of strongly interacting matter and to study the properties of the onset of deconfinement. In order toreach these goals, a study of hadron production properties is performed in nucleus-nucleus, proton proton and proton-nucleus interactions as a function of collision energy and size of the colliding nuclei. In this talk, the newest preliminary results on identified hadron spectra produced in Ar+Sc and Be+Be collisions at six beam momenta (13A, 19A, 30A, 40A, 75A and 150A GeV/c) will be shown. The kinematic distributions and measured multiplicities of identified hadrons will be compared with NA61/SHINE and NA49 p+p and Pb+Pb results, as well as with available world data.

Prof. David Blaschke (UWr & JINR)

Third family of compact stars with a nonlocal chiral quark model EoS

We show that the quark matter equation of state (EoS) obtained within a color superconducting chiral quark model with nonlocal, covariant interactions does not allow for obtaining a third family of hybrid compact stars unless one invokes a density dependence of the vector meson coupling and a density-dependent bag pressure. These density dependences are of the model parameters are obtained from a matching with the string-flip model EoS [Kaltenborn et al., PRD (2017)] for three cases of the screening parameter alpha = 0.20, 0.24, and 0.30. Modern constraints from compact star phenomenology are discussed for these EoS.

Jan Rafelski, Department of Physics, The University of Arizona, Tucson

Probing QGP properties with strangeness

Beginning with the CERN SPS experiments 30 years ago we search for the understanding of how energy becomes matter, that is we study the hadronization of primordial phase of matter, quark-gluon plasma. Today the ALICE is the experiment at the CERN LHC build predominantly to study this process. The key information is derived in study of multistrange hadrons which carry information both, about the process of matter production (hadronization) E => mc^2, as well as about earlier stages when entropy and strangeness are produced. Very recent results show that even a relatively small pp and pA collisions at the LHC energy-scale are creating the new quark-gluon plasma (QGP) phase of matter.

prof. dr hab. Jerzy Kijowski, CFT PAN

The essence of gravity theory

What is gravity? Can it be generalized to an "even more general" General Relativity Theory? Those and similar questions shall be discussed and new perspectives proposed.

Dr Denes Molnar (Purdue University, USA)

Self-consistent viscous phase space distributions from kinetic theory

The main challenge is to describe how local phase space distributions are modified compared to their local equilibrium form in the presence of gradiens and dissipation in the system. In fact, an infinite class of phase space distributions can describe the same hydrodynamic fields. We advocate a self-consistent approach that obtains phase space corrections from relativistic kinetic theory. A both self-consistent shear viscous and bulk viscous phase space corrections calculated for a many component gas of hadrons will be presented and discussed how the corrections affect experimental observables.

prof. dr hab. Henryk Arodź, UJ

On Relativistic Quantum Mechanics of the Majorana Particle

The Hilbert space of states of the relativistic Majorana particle consists of bispinors with real components. The usual momentum operator -i abla can not be defined in such space. Instead of it, we introduce the axial momentum operator p_5 = -i gamma_5 abla. It has rather intriguing properties. In particular, in the case of free massive particle there is an oscillating component, reminiscent of the Zitterbewegung. Next, we accordingly reformulate the plane wave expansion. The time evolution of the modes is given by an SO(4) matrix, which replaces the standard U(1) factor exp(-i E t)

dr hab. Andrzej Dragan (Uniwersytet Warszawski)

Unruh effect for massive fields cannot be detected

Massive particles created in a relativistically accelerated reference frame, as predicted by the Unruh effect, can only be found in a tiny layer above the event horizon, whose thickness corresponds to a single Compton wavelength. This is beyond the reach of any detector and suggests that the Unruh effect may not ever be directly observed for massive fields. The case of massless particles is also examined, for which qualitatively different behaviour is observed in a low-⁠acceleration regime, suggesting that an observation of the Unruh effect for massless particles is more promising.

dr hab. Andrzej Dragan, UW

Relativity vs quantum information

I will discuss some of the most surprising effects of relativity on quantum information science and show how the whole paradigm shifts, when gravity or relativistic motion are taken into account.

dr hab. Dorota Gondek-Rosińska, IA UZ

What can we learn from gravitational waves ?

One of the most important prediction of Einstein's general theory of gravity is gravitational radiation. I will discuss the importance of the recent LIGO and Virgo direct detections of gravitational-waves. The observations of gravitational waves provide a different view on astrophysical processes hidden from electromagnetic astronomy and expand our knowledge of the Universe dramatically. I will outline the current state and the future for gravitational wave astronomy.

dr hab. Chihiro Sasaki

How to give a good seminar

I will give a presentation on soft skills, focusing on the skills how to give a good seminar.

prof. dr hab. Danuta Makowiec, IFTiA UG

Cellular automata approach to cardiac electrophysiology: a toy model or a generative proposition.

Structural modifications of cardiac tissue, caused by disease or/and aging, influence the performance of the heart contraction. Clinicians would like to discern early stages of the tissue impairment based on changes in heart rate. A heart rhythm of a person after heart transplantation is special because is significantly less influenced by autonomic nervous system - the main source of heart rhythm variability in healthy people. Therefore such a rhythm could provide evidences for arrhythmogenic processes developing in the cardiac tissue. The cellular automata model will be discussed, which simulates changes in the atrial tissue and observes effects of these changes on the heart rhythm. We will show that in such approach, we are able to represent reliable and simulation efficiently both electrophysiology of a cardiac cell and tissue organization.

prof. dr hab. Danuta Makowiec, IFTiA UG

Cellular automata approach to cardiac electrophysiology: a toy model or a generative proposition.

Structural modifications of cardiac tissue, caused by disease or/and aging, influence the performance of the heart contraction. Clinicians would like to discern early stages of the tissue impairment based on changes in heart rate. A heart rhythm of a person after heart transplantation is special because is significantly less influenced by autonomic nervous system - the main source of heart rhythm variability in healthy people. Therefore such a rhythm could provide evidences for arrhythmogenic processes developing in the cardiac tissue. The cellular automata model will be discussed, which simulates changes in the atrial tissue and observes effects of these changes on the heart rhythm. We will show that in such approach, we are able to represent reliable and simulation efficiently both electrophysiology of a cardiac cell and tissue organization.

prof. Adam Sawicki (CFT Warszawa)

Odwzorowanie momentu w teorii informacji kwantowej

prof. dr hab. Adam Sawicki, CFT PAN

Quantum entanglement from single particle information

Despite considerable interest in recent years, understanding of quantum correlations in multipartite finite dimensional quantum systems is still incomplete. I will consider a simple scenario in which we have access to the results of all one-particle measurements of such system. The aim is to understand how much information about quantum correlations is encoded in this data. It turns out that mathematically consistent way of studying this problem involves methods that are used in classical mechanics to describe phase spaces with symmetries. In this talk I will review these methods and show their usefulness to our problem.

Ludwik Turko (IFT)

Finite size effects, intermolecular forces and effective virial expansion

A thermodynamically self-consistent model of quantum gas with the effective collective interaction will be presented

prof. dr hab. Adam Miranowicz, UAM

Circuit-⁠QED: Microwave photonics with superconducting quantum circuits

In the past 20 years, impressive progress has been made both experimentally and theoretically in superconducting quantum circuits, which provide a platform for manipulating microwave photons. This emerging field of circuit quantum electrodynamics (circuit-⁠QED) has been driven by the observation of many new interesting phenomena. For instance, the interaction between superconducting quantum circuits and single microwave photons can reach the regimes of strong, ultra-⁠strong, and even deep-⁠strong coupling. Many higher-⁠order effects, unusual and less familiar in traditional cavity QED with natural atoms, have been experimentally observed, e.g., giant Kerr effects, multi-⁠photon processes, and single-⁠atom induced bistability of microwave photons. These developments may lead to improved understanding of the counterintuitive properties of quantum mechanics, and speed up applications ranging from microwave photonics to superconducting quantum information processing [1]. In this talk, I will review experimental and theoretical progress in this rapidly developing field. [1] X. Gu, A. F. Kockum, A. Miranowicz, Y.-⁠X. Liu, and F. Nori: Microwave photonics with superconducting quantum circuits, Physics Reports 718–719 (2017) 1–102.

Valeriya Mykhaylova (IFT)

Transport coefficients of Yang-Mills plasma

OTHER LECTURE, OTHER SUBJECT - beyond this nothing has been changed :-) LT in 2 weeks In the relaxation time approximation, the ratio of the bulk to the shear viscosities is discussed. A recent study including the Gribov parameter exhibits that this ratio goes like what is predicted in the AdS/CFT approach, even at very high temperature. We aim for a better understanding of this result.

Udita Shukla

Colour Evolution of Low-Mas X-ray Binary 4U 1636-536

The work deals with the colour evolution of neutron star low-mass X-ray binary 4U 1636-536 by constructing light curves. 1,476 light curves were extracted corresponding to the energy bands of (2-60) keV, (2.5-5.7) keV and (7.8-16.4) keV. The light curve shows a rough quasi-periodicity of ~ 40-46 days in terms of a clear count rate oscillation. Hardness ratio is found to vary in more or less periodic fashion but being constantly out of phase with the light curve. The hardness-Intensity Diagram has most of the observations clustered in the softer region of the plot corresponding to the banana state whereas, the harder positions or the island state appear as a nearly constant band in the vicinity of 0.5 (Hardness Ratio). Spectra extracted for the energy range (3.0 – 50.0) keV, were fit with a compound model comprising of photo-electric absorption, ‘phabs’, and Blackbody, Gaussian and Comptonizing (high-energy) cut-off. The Gaussian line rises up at ~ 6 keV in the fits. The fit is seen to support the so-called ‘Western’ model (White et al. 1988) comprising of a Comptonizing Accretion Disk Corona (ADC) and the neutron star emitting as a Blackbody. The Blackbody temperature of the neutron star centres around 1 keV to 2 keV, while the (Blackbody) radius broadens as we move from the island to the banana state reaching ~ 1 km, implying that the blackbody emission is from a restricted part of the neutron star.

prof. dr hab. Danuta Makowiec, IFTiA UG

Cellular automata approach to cardiac electrophysiology: a toy model or a generative proposition.

Structural modifications of cardiac tissue, caused by disease or/and aging, influence the performance of the heart contraction. Clinicians would like to discern early stages of the tissue impairment based on changes in heart rate. A heart rhythm of a person after heart transplantation is special because is significantly less influenced by autonomic nervous system - the main source of heart rhythm variability in healthy people. Therefore such a rhythm could provide evidences for arrhythmogenic processes developing in the cardiac tissue. The cellular automata model will be discussed, which simulates changes in the atrial tissue and observes effects of these changes on the heart rhythm. We will show that in such approach, we are able to represent reliable and simulation efficiently both electrophysiology of a cardiac cell and tissue organization.

Dr David Alvarez-Castillo (JINR Dubna)

Compact star tidal deformability constraints from the GW170817 event and their impact on the equation of state

The method of estimation of tidal deformabilities of compact stars and present results for pure hadronic as well as hybrid stars that include the mass twins case will be presented. Then the recent GW170817 compact star tidal deformability constraints that serve to estimate radius values related to the stiffness of compact star matter will be analyzed.

prof. dr Luciano Rezzolla, Goethe University, Frankfurt (Main)

Binary neutron stars: Einstein's richest laboratory

I will argue that if black holes represent one the most fascinating implications of Einstein's theory of gravity, neutron stars in binary system are arguably its richest laboratory, where gravity blends with astrophysics and particle physics. I will discuss the rapid recent progress made in modelling these systems and show how the inspiral and merger of a binary system of neutron stars is more than a strong source of gravitational waves. Indeed, while the gravitational signal can provide tight constraints on the equation of state for matter at nuclear densities, the formation of a black-hole--torus system can explain much of the phenomenology of short gamma-ray bursts, while the the ejection of matter during the merger can shed light on the chemical enrichment of the universe.

Jakub Poła

CFD-DEM methods for simulations of proppants transport in hydraulic fractures

As part of my speech, I will present all the issues that I dealt with during the ShaleMech project. I will discuss the concept of CFD-DEM method in approach of resolved and unresolved, the way to take into account the effect of particle rotation in simulation and the model of particle collision correction in two-phase systems. In the final part, I will present applications of the CFD-DEM method for simulation of proppants transport in various systems and the use of the CFD-DEM method for studying porous systems.

prof. dr hab. Ewa Rondio, NCNR.

Neutrino Properties Determined in Oscillation Experiments

Neutrinos are the lightest of known subatomic matter particles in the set of building blocks of matter. In the Standard Model there are three types of neutrinos, associated with respective charged leptons. Prof. F. Reines who was the author of first experiment which detected neutrino said about them, that they are "the smallest part of reality ever invented by human". In the presentation experimental results proving specific features of neutrinos will be presented, as well as some information on neutrino sources and detection techniques. In general neutrino oscillations can occur only when the mixing parameters, including squere of mass difference, are non-zero. Therefore, observation of neutrino oscillations proves that neutrinos are not massless. With several experiments contributing, one can show that we know the oscillation parameters quite well. The most recent oscillation results from neutrinos and antineutrinos will be presented and also future long baseline oscillation projects in short and long time scale will be briefly mentioned.

Dr Gábor Balassa (Wigner Research Centre for Physics, Hungarian Academy of Sciences)

Non-equilibrium Charmonium dynamics in heavy-ion collisions

The masses of the low lying charmonium states, shifted downwards due to the second order Stark effect. In pbar Au collisions at 6−10 GeV we study their in-medium propagation.The time evolution of the spectral functions of these charmonium states are studied with a Boltzmann Uehling-Uhlenbeck (BUU) type transport model. The in medium mass shift of these states can be observed in the dilepton spectrum, therefore, by observing the dileptonic decay channel of these low lying charmonium states, especially for PSI(3686), one can gain information about the largeness of the gluon condensate in nuclear matter. The methods used to calculate the elementary cross sections with charmonium in the final states are also discussed.

dr Paweł Laskoś-⁠Grabowski, IFT Uwr

Online algorithms for physicists

In the name of the field of online algorithms, "online" does not refer to computer networks, but instead to making decisions based on partial information, which is revealed only over time. Algorithms are primarily analysed in terms of their incurred cost (or, conversely, accumulated gain) and how it compares to an optimal offline (that is, omniscient or prescient) solution. As such, this situation is different from more traditional algorithm analysis, which focuses on time and/or space complexity. In this talk, I will provide a brief overview and introduction into online algorithms. I will introduce the central concept of competitiveness and walk through several typical problems, from toy examples to more realistic ones. The pretext for this talk is an article I co-authored, „Logarithmic price of buffer downscaling on line metrics” [arXiv:1610.04915], recently published in Theoretical Computer Science, which I hope to briefly cover, but which will by no means be the main focus of the talk.

Beata Kowal

Polarization Transfer in Weak Pion Production off the Nucleon

During my presentation I will present results of the investigation of the polarization transfer observables in the single pion production in neutrino-nucleon scattering and methods for obtaining them. My presentation bases on the papers PhysRevD.97.013001 and APhysPolB.48.2219.

Beata Kowal

Polarization Transfer in Weak Pion Production off the Nucleon

During my presentation I will present results of the investigation of the polarization transfer observables in the single pion production in neutrino-nucleon scattering and methods for obtaining them. My presentation bases on the papers PhysRevD.97.013001 and APhysPolB.48.2219.

prof. dr hab. Andrzej Królak, IMP

Gravitational wave astronomy - a new window on the Universe

I shall present first detections of gravitational wave signals from merging compact binary systems of black holes and neutron stars made by LIGO and Virgo detectors. I shall focus on the recent first detection of the gravitational wave signal from coalescence of two neutron stars and accompanying observations of gamma ray bursts and kilonova. I shall briefly describe the phenomenon of gravitational radiation in general theory of relativity. I shall explain basic principles of the laser interferometric gravitational wave detector. I shall present data analysis methods used in the detection of gravitational wave signals in the noise of the detectors. I shall present consequencies of the detections for fundamental physics and astronomy. I shall describe contribution of Polish scientists into this discovery.

Rafał Topolnicki

Kilka słów o wybranych problemach statystyki matematycznej.

W referacie omówione zostaną dwa problemy z dziedziny teoretycznej statystyki matematycznej: (1) semiparametyczna estymacja krzywej ROC, (2) estymacja ilorazu procesu geometrycznego. W obu tych problemach wykorzystanie znajdują estymatory najmniejszej odległości. Dla krzywej ROC, która używana jest do oceny jakości klasyfikatorów binarnych, rozpatrzone zostaną dodatkowo metody estymacji nieparametrycznej, ze szczególnym uwzględnieniem tych wykorzystywanych w problemie estymacji dystrybuanty. Omówię również metodę wielowymiarowej estymacji jądrowej oraz jej praktyczne zastosowanie na przykładzie analizy trajektorii symulacji dynamiki molekularnej. Wystąpienie zostanie poprzedzone krótki wstępem do statystki matematycznej oraz teorii estymacji.

dr Marcin Dąbrowski, PIB Wrocław, UiO Oslo

Computational Geology

I will first briefly introduce the physics behind both the natural and technological processes operating in geological media. Some of the geological processes evolve over millions of years and they cannot be directly reproduced in laboratory experiments. In our studies, we use computer modelling to understand how the natural processes lead to the formation of geological structures on various length scales, and how such structures may influence the technological processes. Rocks are strongly heteregeneous, often anisotropic, and typically non-linear materials. To gain some fundamental insights into the studied systems, we use simplified models and analytical solutions, and we resort to numerical methods to quantify the behavior of real complex systems. I will show a few examples of the relevant analytical solutions, and present some basic characteristics of our numerical approaches. Finally, I will give an overview of our modelling studies spanning a range of topics, from rock deformation modelling, suspension dynamics, thermochemical convection, to fluid flow in rock fractures.

Maciej Lewicki

On Strangeness in NA61/SHINE

NA61/SHINE is a fixed target experiment at the CERN Super-Proton-Synchrotron. The main goals of the experiment are to discover the critical point of strongly interacting matter and to study the properties of the onset of deconfinement. In order to reach these goals, a study of hadron production properties is performed in nucleus-nucleus, proton-proton and proton-nucleus interactions as a function of collision energy and size of the colliding nuclei. One of the predicted signatures of the onset of deconfinement are substantial changes in dynamics of strangeness production. In this talk, I will give an overview of statistical and dynamical models of strangeness production in the vicinity of phase transition. Predictions of the models will be compared with available results on heavy-ions collisions, including new results on intermediate mass systems from NA61/SHINE.

prof. dr hab. Stanisław Drożdż, IFJ PAN

Multiscale correlations in narrative texts

A language constitutes a great complexity as it for language is especially true that ”more is different”. Thus, the most natural linguistic constracts to study quantitative characteristics of the linguistic complexity are sentences and their mutual arrangement in texts. Studying in particular the sentence length variability (SLV) in a large corpus of world-famous literary texts shows that it involves a cascade-like alternation of various lengths sentences such that the power spectra S(f) of thus characterized SLV universally develop a convincing 1/f-type scaling with exponents close to what has been identified before in musical compositions or in the brain waves. An overwhelming majority of the studied texts simply obeys such fractal attributes but especially spectacular in this respect are hypertext-like, "stream of consciousness" novels. In addition, they appear to develop structures characteristic of irreducibly interwoven sets of fractals called multifractals which indicates that the related long-range correlations carry even a nonlinear component. This points to a distinct role of the full stops recurrence times along texts in inducing the long-range correlations. Treated as one extra word, the full stops at the same time appear to obey the Zipfian rank-frequency distribution, however. Furthermore, it appears that, from a statistical viewpoint, all the punctuation marks reveal properties that are qualitatively similar to the properties of the most frequent words.

dr Marcus Bluhm, IFT UWr

Competing for perfection – Ultracold Fermi gases can be as perfect liquids as the superhot Quark-Gluon Plasma

The properties of ultracold atomic gases have been investigated with increasing attention in recent years. The possibility to easily control physical parameters and manipulate the atomic interaction strength makes these gases very attractive to better understand other strongly coupled quantum systems. For example, expansion experiments with trapped ultracold Fermi gases (UFGs) show a similar flow pattern of the matter as the one deduced from particle spectra measured in high-energy nuclear collisions. This leads to the conclusion that UFGs can form quantum fluids with similar properties as the superhot Quark-Gluon Plasma (QGP) created in the nuclear collisions. In this talk, the flow behavior of both UFGs and QGP will be confronted. By comparison with expansion data, the shear viscosity of strongly coupled UFGs will be deduced and shown to be comparably small with the QGP close to the lower bound imposed by the gravity – field theory duality. Interesting future directions (in both fields) will be discussed, which can help to reveal the astonishing similarities in these two quantum fluids.

Michał Szymański

Polyakov loop fluctuations in the presence of external fields

One of important goals of high energy physics is to understand the deconfinement - liberation of quarks from hadrons under extreme temperatures and densities. For systems with small net quark number density many insights are provided by first-principle lattice QCD calculations. Especially important are results on Polyakov loop which plays the role of an order parameter of deconfinement in the limit of infinitely heavy quarks and serves as an approximate order parameter in systems with dynamical quarks. In this talk I will focus on ratios of Polyakov loop susceptibilities and argue why these quantities may be considered as excellent probes of deconfinement. I will also discuss an effective model which captures trends in recent lattice QCD data on these ratios.

dr Jakub Bilski

Fenomenology of quantum general relativity: idea, difficoulties and possible predictions

During the seminar I will briefly introduce my idea of a canonical quantization under restrictions of general relativity. First I will show how a proper choice of canonical variables leads to the manifestly diffeomorphism invariant description of a quantum field. Next I will present a list of assumptions and simplifications that I will use in direct calculations. Then I will sketch the main steps in the derivation of quantum corrections coming from the gravitational degrees of freedom on the example of the scalar field. Discussing phenomenological applications of my result, I will consider possibilities of proving the assumptions and generalizing the simplifications from the first part of my talk.

dr Ewa Niemczura, IA UWr

Seven terrestrial planets around the nearby ultra-cool dwarf star TRAPPIST-1

Almost a year ago Michaël Gillon and collaborators (Nature 542,456–460; 2017) announced the discovery of a system of seven terrestrial planets around the ultra-cool dwarf star TRAPPIST-1. For many reasons this is an extremely interesting system. All the planets are tightly packed together and in orbital resonance. They have radii, masses, and densities close to those of the Earth, which means, they are so called terrestrial-type planets. Furthermore, their orbits inclination with respect to the observer allows to study their atmospheres and, eventually, to decide if they can be habitable. The TRAPPIST-1 system provides a planetary-scale laboratory, ideal for testing theories and models concerning planetary formation and evolution, atmospheres, interplanetary interaction and potential for habitability.

Tomasz Wysoczański

Propozycja prostego modelu wzrostu mikrostruktur z zawiesiny cząstek.

[Seminarium robocze] Na seminarium chciałbym zaprezentować pomysł względnie prostego modelu budowania mikrostruktur przy pomocy siły dielektroforetycznej. Przedstawię szczegóły modelu, jego działanie oraz parametry. Ponadto omówię otrzymane wyniki, porównując je z obserwacjami eksperymentalnymi. Pokrótce o modelu: przedstawia on zawiesinę cząstek (budulca) oraz mikroelektrody. Układ zdefiniowany jest na sieci kwadratowej. Cząstki i elektrody są opisywane przez zajęte węzły tej sieci. Ruch cząstek jest realizowany przez losowe przejścia między sąsiednimi węzłami. Budowanie struktury polega na dołączaniu cząstek do elektrody, jeżeli dojdzie do kolizji cząstka-elektroda (podobnie jak w agregacji ograniczonej dyfuzją). Zarówno na ruch cząstek, jak i przyłączenie do elektrod narzucone zostały dodatkowe warunki, mające odzwierciedlić działanie siły dielektroforetycznej.

UNUSUAL TIME and PLACE! Prof. Marek Gazdzicki (UJK Kielce and Frankfurt Univ.)

On Transitions in High Energy Nuclear Collisions; News from NA61/SHINE at CERN SPS

NA61/SHINE is a fixed target experiment at the CERN SPS. The main goals of the experiment is to discover the critical point of hadronic matter and to study the properties of the onset of deconfinemnt. Prof. Gazdzicki is the spokesperson of the NA61/SHINE Collaboration.

Beata Kowal

Polarization transfer in SPP in neutrino-nucleon scattering

I will present results of the investigation of the polarization transfer observables in the single pion production in neutrino-nucleon scattering and methods for obtaining them. My presentation bases mainly on the paper "Polarization transfer in weak Pion production off the nucleon" and less on the proceedings "Single pion production in neutrino-nucleon scattering studied with FORM package".

dr Tomasz Golan, UWr

Machine Learning for MINERvA Physics Reconstruction

There has been growing interest in machine learning methods in last years from both scientists and information technology companies. Mainly due to better access to big data and the development of parallel computations techniques using graphics processing units. The rapid development of algorithms, in particular those related to artificial neural networks, makes it possible to apply modern approach in data analysis. The methods becomes more and more popular in high energy physics. MINERvA is a neutrino experiment located at Fermilab. The unique design of the detector allows to measure cross sections on different nuclear targets. The crucial part of data analyses is the procedure of the events reconstruction. Recently, convolutional neural networks are used for the task. First results indicate the increase of an accuracy, comparing to standard reconstruction methods. During the seminar I will introduce briefly the MINERvA experiment and cover the basis of machine learning methods used for the vertex position reconstruction. It will be followed by preliminary results obtained for different nuclear targets.

Mateusz Cierniak

Vector-interaction-enhanced bag model

For studies of quark matter in astrophysical scenarios the thermodynamic bag model (tdBag) is commonly employed. This model approximates the effect of quark confinement, but it lacks other important properties of Quantum Chromodynamics. The vector-interaction-enhanced bag model (vBAG) improves the tdBAG approach by taking into account dynamical chiral symmetry breaking and repulsive vector interactions. The latter is of particular importance to studies of dense matter in beta-equilibrium in order to explain the 2 solar mass maximum mass constraint for neutron stars. Another particular feature of vBag is the determination of the deconfinement bag constant (Bdc) from a given hadronic equation of state (EoS) in order to ensure that chiral and deconfinement transitions coincide. The model can be derived from the QCD based framework of Dyson-Schwinger equations by assuming a simple quark-quark contact interaction. This work will focus on the resulting neutron star equations of state.

Maria Gieysztor

Quantum discord in bipartite 2 & 3 level systems

Considering composite quantum systems one can ask whether the system behaves in a classical or quantum way. This is related to the type of correlations between their subsystems. I will start my presentation with introducing the classification of composite quantum systems and in the following parts I will elaborate mainly on the quantum correlations. I will explain the notion of quantum discord as a measurement induced informational measure of quantum correlations and discuss it's properites. Moreover, methods for quantum discord investigation in bipartite two-level systems will be presented along with the difficulties arising when moving to higher level systems.

Jan Sobczyk

NuWro and recent T2K/MINERvA CC0Pi data

I will discuss problems with describing recent CC0Pi data. Several data/MC, or more precisely data/NuWro tensions are clearly seen.

prof. Jan Rafelski, University Tuscon

Something STRANGE is Flying Around

Are there compact ultra-dense objects (CUDOs) in the Universe? A few CUDO candidates are STRANGElet = fragments of neutron stars, dark matter bound objects, micro-black-hole. Could CUDOs have collided with solar system bodies and the Earth? If so: the high density of gravitating matter provides the distinct observable, the surface-penetrating puncture -- shot into, and even through, a moon or the planet. Only a fraction of the CUDO kinetic energy is damaging the entry/exit surface regions. For such exotic matter each planet or moon is a macroscopic detector accumulating signal over geological time scale. CUDOs maybe recognized by the coincident impactor hit with a singular high atmosphere volcanic eruption. Rocky objects in solar system accumulate impact scars for billions of years. Asteroid belt could harbor captured CUDOS.

prof. Jan Rafelski (Tuscon University, AZ, USA)

Time Evolution of Hot Hagedorn Universe

The task: connect the present day visible Universe with prior eras, back to primordial conditions at and above Hagedorn temperature, the point of creation of matter as we know it. Matter and antimatter emerged from Quark_Gluon Plasma when the Universe was 13 microseconds old. A nano-fraction surplus of matter survives the ensuing annihilation process. A dense electron positron-photon-neutrino plasma evolves. Electrons and positrons annihilate while neutrinos decouple. All this takes less than a second, this creates the context for the big-bang nucleo-synthesis and ultimately leads to the visible Universe around us. The continuous evolution across many evolutionary eras will be discussed and the Universe energy composition across cosmological history illustrated.

prof. Peter Petreczky, BNL

Supercomputing the Matter at Extremes: From Hadrons to Quarks

At very high temperatures the strongly interacting matter is expected to undergo a transition to a new state, where the dominant degrees of freedom are quarks and gluons instead of hadrons. I will discuss this transition and the properties of the new form matter based on large scale numerical calculations within lattice regularized Quantum Chromodynamics (LQCD). In particular, I will discuss equation of state, Debye screening and fluctuations of conserved charges. I will show how the fluctuations of conserved charges can be used to understand the transition from hadrons to quarks. I will also compare the numerical LQCD results with pictcure based on weakly interacting gas of quarks and gluons.

Piotr Brzeski

Percolation of hyperspheres

A new method of studying the continuous percolation of aligned objects was recently proposed by Z. Koza and J. Poła in their article entitled "From discrete to continuous percolation in dimensions 3 to 7". Using this method authors were able to obtain results for percolations of hypecubes with far better accuracy than attained with any other method before. In my presentation I will describe aforementioned method and its application to percolation of hyperspheres in multidimensional systems.

Tomasz Golan

Make your scientific software portable with Singularity containers

Containers allow to encapsulate software with all dependencies - libraries, data, operating system (OS) - into a single executable file. It helps to make your scientific packages ultra portable with a possibility to run them on any machine and any OS. During the seminar I will introduce Singularity containers, which are primarily used by scientific applications users. I will cover the basic concept of a software container and demonstrate how to use, create (interactively and using recipes), and share containers. Finally, I will present Singularity Hub and its integration with GitHub for build automation.

dr Raúl González Jiménez, Ghent University

Modeling neutrino-nucleus interaction for neutrino-oscillation experiments

Neutrino properties have been investigated for more than 80 years. It has been firmly established that neutrinos oscillate and hence are massive particles. The oscillation parameters have been measured, but still one needs to determine the neutrino-mass hierarchy, the neutrino-mass absolute scale, and whether the neutrino is a Dirac or a Majorana particle. Also, investigation of charge-parity (CP) violation in the leptonic sector of the Standard Model is of fundamental importance for the construction of cosmological models. Today, huge efforts in both theoretical and experimental sides are made to achieve these goals. Inevitably, this ambitious scientific program meets challenges that slow down the process. The underlying problem is that the energy of the incident neutrino, which is a necessary input for the oscillation analyses, is unknown. The neutrino energy is reconstructed using the available experimental information and theoretical models. What complicates the reconstruction of the neutrino energy, and brings theoretical nuclear physics to the stage, is the fact that all present and future generations of neutrino-oscillation experiments use complex nuclei as target/detector material. I will present an overview of some theoretical approaches employed for the modeling of the main reaction mechanisms involved in the neutrino-nucleus interaction.

Kajetan Niewczas

Nuclear Transparency: NuWro vs Data

Final state interactions (FSI) play an important role in the description of lepton-nucleus interactions. Nuclear transparency is a measure that allows for a qualitative comparison between FSI models and available experimental data. I will show the methods for a reliable comparison between the data from electron scattering experiments and neutrino scattering Monte Carlo event generators. Then I will present the preliminary results of such tests carried out on the intranuclear cascade model implemented in NuWro.

Dr Marek Szczepanczyk (LIGO Scientific Collaboration/Embry-Riddle Aeronautical University, USA)

UNUSUAL DAY Gravitational Waves Core-Collapse Supernova Science with Advance and Third Generation Interferometers

Core-Collapse Supernovae(CCSNe) are the spectacular and violent deaths of massive stars. The study of Gravitational Waves (GW) from CCSNe give us information about the physical properties of the collapsed core and elucidate the explosion mechanism and can help elucidate the explosion mechanism as well unknown physics (silent supernovae or quark stars). I will review the state-of-art techniques used to search for GW from CCSNe and current work on detection perspectives with future GW Observatories. The reconstruction of the waveform and extraction of physical information is a difficult task. It requires a deep understanding of multi-dimensional CCSN simulations, data analysis caveats, detector response, as well as understanding how insights provided by neutrino and electromagnetic messengers help us extract GW signals from the detector noise. In the LIGO/Virgo Supernova Working Group we work on all aspects leading to direct detection of GW from CCSN and extracting physical information. I will talk about properties of the CCSN waveforms, their deterministic and non-deterministic components, algorithm development that uses the deterministic features (like g-modes) used to increase the visible distance for CCSN detection. I will also review the detection range, future algorithm developments and detection capabilities with the designs of future detector configurations.

dr Tomasz Wasak, UW

"Quantum interferometry with ultracold atomic gases"

Creation of ultracold atomic ensembles triggered the studies of fundamental aspects of quantum mechanics. In manybody systems, the ability to generate non-classical correlations between atoms opened the possibility for their practical applications in non-trivial ways, for example in quantum computation or quantum-enhanced metrology. However, before the implementation stage, we must first make sure that the entanglement is present in the system, which is often a difficult task. In this talk, I will describe experiments that were conducted to verify existence of non-classical correlations in ultracold atomic systems. I will describe criterions by which the nonclassicality was certified, and how these measures are related to interferometry. In a special class of experiments, two groups of atoms are produced in which the non-classicality stems from indistinguishability between pairs of particles. I will show how these correlated pairs of atoms are generated, and how they can be used for quantum-enhanced interferometry or fundamental tests of quantum mechanics, like the violation of Bell's inequality.

Mateusz Bancewicz

Simulations of fluid-granular systems with application to shale gas extraction

In this presentation I will summarize two years in ShaleMech cooperation, a project that was devoted to the intensification of shale gas extraction. A brief introduction will be given, including an explanation of gas reservoir stimulation process and a description of utilized numerical methods (Lattice Boltzmann Method and Discrete Element Method). Then, I will show simulations that reproduce proppant transport in microfractures, which efficiency is crucial to successful gas extraction. A the end I will compare my approach to the one taken by my colleague.

Mateusz Bancewicz

Simulations of fluid-granular systems with application to shale gas extraction

In this presentation I will summarize two years in ShaleMech cooperation, a project that was devoted to the intensification of shale gas extraction. A brief introduction will be given, including an explanation of gas reservoir stimulation process and a description of utilized numerical methods (Lattice Boltzmann Method and Discrete Element Method). Then, I will show simulations that reproduce proppant transport in microfractures, which efficiency is crucial to successful gas extraction. A the end I will compare my approach to the one taken by my colleague.

Josua Unger

Supersymmetry Invariance of Dimensional Reduction Applied to Higgs Boson Mass Calculations

The Higgs boson mass is an important observable that can be calculated in supersymmetric quantum field theories. Since it is measured with high precision it is valuable to consider higher order contributions in the perturbation theory to this mass. In order to perform such loop calculations one has to regularize the underlying quantum field theory. Even though there are many equivalent regularization schemes it is more convenient to use a scheme which preserves the symmetries of the model at the regularized level. In the work underlying this talk, the aspects of supersymmetry and gauge symmetry which are relevant for the form of the Higgs boson mass are determined. These aspects, represented by Slavnov-Taylor identities, are then investigated in dimensional reduction, a regularization scheme designed to conserve supersymmetry, for a potential breaking. A result of the examination is the symmetry conservation of dimensional reduction in the Minimal Supersymmetric Standard Model up to the three-loop level if the gaugeless limit is considered. Additionally it is shown that the treatment of traces containing γ5 in dimensional reduction leads to non-trivial expressions for the breaking at the two-loop level in a general gauge theory.

dr Marcin Misiaszek, UJ

New results on solar neutrinos from Borexino

Solar neutrinos emitted by fusion reactions occurringin the Sun provide a unique and direct way to study theinterior of our star.The 50-year-long experimentaleffort to study solar neutrinos has been extremelyrewarding both in terms of solar physics, by confirmingthe Standard Solar Model (SSM) predictions, and interms of particle physics, by giving a substantial contribution to the discovery of neutrino flavour oscillations.The Borexino liquid scintillator (LS) neutrino observatory is devoted to performing neutrino observations, and is optimized for measurements in the low energy (sub-MeV) region of the solar neutrino spectrum. Borexino has performed the first direct, high-precision, wideband solar neutrino spectroscopy of the solar neutrino spectrums main components, including improving the knowledge of the CNO neutrino flux. Inthe presentation,the first simultaneous precision measurementof the interaction rates of solar neutrinos will be reported.

Tomasz Wysoczański

Dielectrophoresis and other electrokinetic phenomena in microsystems – an introduction

Dielectrophoresis and other electrokinetic phenomena in microsystems – an introduction Dielectrophoresis (DEP) is a phenomenon in which force acts on polarizable particles in an inhomogeneous electric field. Depending on various parameters, dielectrophoretic force can attract particles to or repel them from areas of high electric field. DEP is often accompanied by other electrokinetic phenomena, such as induced-charge or AC electroosmosis. DEP can be applied to the fabrication of miniaturized laboratory devices (lab-on-a-chip), as well as assembly of micro and nanostructures. This presentation is an overview of electrokinetic phenomena that affect the process of assembly of nanoparticles into nanostructures. This overview will be accompanied by finite element calculations.

Tomasz Wysoczański

Dielectrophoresis and other electrokinetic phenomena in microsystems – an introduction

Dielectrophoresis (DEP) is a phenomenon in which force acts on polarizable particles in an inhomogeneous electric field. Depending on various parameters, dielectrophoretic force can attract particles to or repel them from areas of high electric field. DEP is often accompanied by other electrokinetic phenomena, such as induced-charge or AC electroosmosis. DEP can be applied to the fabrication of miniaturized laboratory devices (lab-on-a-chip), as well as assembly of micro and nanostructures. This presentation is an overview of electrokinetic phenomena that affect the process of assembly of nanoparticles into nanostructures. This overview will be accompanied by finite element calculations.

Prof. Evgeny Ivanov

Deformed supersymmetric quantum mechanics with spin variables

A model of the SU(2|1) supersymmetric quantum mechanics with additional semi-dynamical spin degrees of freedom is studid. The energy spectrum and the full set of physical states are found as functions of the deformation parameter m and SU(2) spin q. The states at the fixed energy levels form irreducible multiplets of the supergroup SU(2|1). The hidden superconformal symmetry OSp(4|2) of the model is revealed and shown to play a role of the spectrum-generating algebra. Some further generalizations are sketched. Based on arXiv:1710.02130 [hep-th] (in collaboration with Sergey Fedoruk and Stepan Sidorov).

Valeriya Mykhayova

Transport Coefficients of the Quark-Gluon Plasma within the Relaxation Time Approximation

The analysis of experimental data obtained in heavy ion collisions at RHIC and LHC showed that the evolution of the quark-gluon plasma (QGP) is well described by nearly ideal hydrodynamics. However, even small dissipative processes which appear in QGP should be taken into account. Then QGP is described by relativistic viscous hydrodynamics, characterized by the transport coefficients, for example, the shear η and the bulk ζ viscosities. The values and properties of these parameters not only carry the information on how far the system appears from an ideal hydrodynamics but also provide a relevant insight into the hydrodynamic evolution of a fluid. During the talk, I will show how to obtain viscosity coefficients of the QGP using the relaxation time approximation to Boltzmann equation.

Michał Marczenko - IFT

Net-baryon number fluctuations in the quark-meson-nucleon model at finite baryon density

One of the most significant aspects of QCD thermodynamics is understanding how the transition from hadrons to their constituents—quarks and gluons—relates to the underlying deconfinement and chiral dynamics. This is of major relevance for heavy-ion collisions, as well as in the study of cold and dense systems, such as compact stars. The latter, however, is often studied exclusively in models of either hadron or quark degrees of freedom. In this talk, we present the mean-field thermodynamics of an effective hybrid quark-meson-nucleon (QMN) model for QCD phase transitions at low temperatures and finite baryon densities. In this framework, the chiral dynamics is described within the linear sigma model, whereas the deconfinement transition is driven by a medium-dependent modification of the particle distribution functions, where an additional scalar field is introduced. The structure of the net-baryon number fluctuations along with its higher order cumulants is discussed as possible probes for the chiral and deconfinement phase transitions. A qualitative comparison of the results obtained in the nucleonic (parity doublet) and quark (NJL) models is also presented.

dr Mariusz Żaba, UO

Stany związane operatorów nielokalnych.

Procesy losowe z gaussowskim szumem były od dziesięcioleci intensywnie badane, począwszy od pionierskich prac Smoluchowskiego na temat ruchów Browna. Należą one do szerszej klasy procesów, o niezależnych i stacjonarnych przyrostach, nazywanych procesami Levy. Pojawiające się liczne przykłady eksperymentów, w których ewolucja jest wyraźnie niegaussowska, skłaniają do poszukiwania sposobów ich opisu, szczególnie na poziomie mikroskopowym. Jedną z takich metod jest tzw. ułamkowa mechanika kwantowa, gdzie zwykły Laplasjan zastępujemy pochodną ułamkową. Przedstawię sposoby rozwiązywania zagadnień spektralnych operatorów nielokalnych więzionych pewnymi potencjałami.

Aleksander Kozak

Scalar-tensor gravity in the Palatini approach

Both scalar-tensor theories and Palatini formalism are means of alternating classical theory of gravity in order to account for phenomena being seemingly unexplainable on the ground of the Einstein theory, or to serve as toy models used to test limitations of the theory in question [1]. In the literature both Palatini approach and scalar-tensor theories have been widely discussed, but there are very few - if none - authors writing about a merge of these two ideas. During the seminar I will present a possible action functional for such class of theories. We aim at analysing the theory using the language of invariants, allowing us to write down all equations in a way independent of our choice of the conformal frame [2]. Two frames most frequently used in the literature will be also discussed: Einstein and Jordan frame. The mathematical machinery will be then applied to f (R) theories, enabling us to obtain Friedmann equations and investigate inflationary behaviour in the Starobinsky model. [1] S. Capozziello, V. Faraoni, Beyond Einstein Gravity: A Survey of Gravitational Theories for Cosmology and Astrophysics, Springer (2011) [2] L. Jarv, P. Kuusk, M. Saal, O. Vilson, Invariant quantities in the scalar-tensor theories of gravitation, Phys. Rev. D 91, 024041 (2015)

dr hab. Tobias Fischer, UWr

The origin of heavy elements in the universe

The production of elements heavier than iron in the universe poses sever challenges to the current understanding of explosive cosmic events. In particular during the early evolution of our galaxy, when the metal content known as metallicity was generally low, the explosions of massive stars was the major site, if not the only one. Even though the heaviest elements, e.g., Gold, Lead and even the actinide elements such as Uranium and Plutonium are robustly produced in the violent event of two merging neutron stars, they can have no contribution to the chemical enrichment of the galaxy at vanishing metallicity. It leaves the explosions of massive stars as only site, for which I will review in this talk our current picture of the associated synthesis of heavy elements, which canonically yields the production of elements with atomic numbers only up to 32<Z<50 such as Zirconium and Strontium. It emphasizes the puzzle of the observed enrichment of metal-poor stars with significantly heavier elements, while simultaneously pointing to a few rare events associated with massive star explosions that enriched the galaxy with these elements at low metallicity. Still today, their origin and nature is yet to be discovered.

Maciej Matyka

Transport płynu przez ośrodki porowate (Robocze)

W związku z wyjazdem na UW do Warszawy za tydzień chciałbym wygłosić próbne wystąpienie. Tematem przewodnim seminarium będzie przepływ przez struktury porowate oraz trzy główne zagadnienia, którymi się do tej pory zajmowaliśmy: krętość, funkcja rozkładu prędkości oraz najnowsze badania dotyczące granicy laminarnego przepływu cieczy. Zapraszam - seminarium jest robocze (właśnie je przygotowuję), dlatego każda uwaga mile widziana, szczególnie zależy mi na osobach nowych w tej tematyce.

prof. dr hab. Jakub Zakrzewski, UJ

Periodic driving as a tool towards a quantum simulator.

Cold atomic systems form a versatile, well controlled tools that enable modeling of different quantum phenomena. In that sense they fulfil the requirement for a quantum symulator as envisioned by Feynman – one may build up well controlled systems that model physical situations difficult to analyse by standard theoretical tools. I hope to show the examples where controlled periodic driving of cold opticla systems enables modelling of nontrivial topological models, fractional quantum Hall effect or dynamical gauge fields.

Daniel Frączek

Charakterystyka wieloskalowa niejednorodności materiałów wielofazowych oraz modelowanie ich właściwości efektywnych

W niniejszej rozprawie przedstawiam i uogólniam metodę wieloskalowych deskryptorów entropowych zastosowaną do opisu stopnia przestrzennej niejednorodności materiałów wielofazowych. W wyniku otrzymano nowe fazowe deskryptory entropowe, które pozwalają na analizowanie ilościowo cech rozmieszczenia przestrzennego każdej z faz. Metodę entropową zastosowano do przeprowadzenia statystycznej rekonstrukcji trójwymiarowych materiałów wielofazowych korzystając z niepełnej informacji mikrostrukturalnej zawartej w pojedynczym przekroju i ujawnionej przez ogólny deskryptor entropowy. Rekonstrukcję przeprowadzono stosując różne metody, w tym nowe podejście prawa potęgowego z dwoma wykładnikami. W rozprawie przeanalizowano różne fizyczne podejścia do obliczania efektywnego przewodnictwa elektrycznego, koncentrując się na modelach sieciowych o niskich kosztach obliczeniowych z lub bez oddziaływania pomiędzy elementami fazy wysoko przewodzącej. Wyróżniającym się podejściem w przypadku braku oddziaływania jest prosty wariant przestrzennej grupy renormalizacyjnej. Metodę tę wykorzystano do poszukiwania możliwej relacji pomiędzy kontrolowanymi zmianami prototypowych mikrostruktur a ich efektywnym przewodnictwem elektrycznym.

Lennart Brocki

Cold Inflation versus stochastic inflation

The two dynamical realizations of cosmological inflation are discussed, cold and stochastic inflation. After reviewing the description of the expansion of the Universe and different cosmological models it is explained how inflation solves the flatness and horizon problem. It is shown how the fluctuations of the inflaton lead to scale-invariant density fluctuations. The power spectrum of fluctuations in de Sitter space is calculated for a quantized and for a stochastic scalar field.

Kajetan Niewczas

Nuclear Transparency: NuWro vs Data

Final state interactions (FSI) play an important role in the description of lepton-nucleus interactions. Nuclear transparency is a measure that allows for a qualitative comparison between FSI models and available experimental data. I will show the methods for a reliable comparison between the data from electron scattering experiments and neutrino scattering Monte Carlo event generators. Then I will present the preliminary results of such tests carried out on the intranuclear cascade model implemented in NuWro.

dr Pasi Huovinen, UWr

I can't believe it's fluid! -⁠ when fluid dynamics describes systems the size of atomic nuclei

We know fluid dynamics as a powerful description of the behaviour of macroscopic amounts of liquids and gases, but it turns out that fluid dynamics can describe even a droplet of fluid of the size of atomic nuclei -⁠ if the droplet of fluid consists of free quarks and gluons. In this talk I will review what such a state of free quarks and gluons, called quark-⁠gluon plasma, is, how it is created in heavy-⁠ion collision experiments, and how we use fluid dynamics to describe the evolution and properties of this plasma.

Dr Heiko Moller (Uniwersity of Darmstadt)

Evolution of intermediate-mass stars

In this talk, an overview of evolution and fate of stars from a numerical modeling perspective will be presented. Particular focus will be put on stars ranging between 8 to 12 times the mass of the sun. These stars are of great interest in stellar physics, as they denote the transition region of the less massive stars that end their lives as White Dwarfs and the massive stars that become gravitationally unstable, explode in a core-collapse supernova and either become a Neutron star or a Black Hole. Recent investigations indicate that the fate of intermediate-mass star is very sensitive to uncertainties of occurring nuclear reactions. We show that the temporal evolution in the stellar core is significantly altered by the occurrence of beta-decay and electron-capture processes on nuclei in the sd-shell.

On Monday!!! - Prof. Teiji Kunihiro (Kyoto Univ.)

On Monday!!! Precursory Phenomena of QCD Phase Transitions in Hot and Dense Matter

The talk consists of two parts. In the first part, I discuss possible scenarios of the way how chiral restoration manifest itself in the spectral functions in hadron channels, partly based on our recent work (P.Gubler, T.K. and S.H.Lee, PLB767(2017),336. The second part is devoted to clarifying the nature and the properties of the soft mode of the QCD Z2 critical point(CP) on the basis of the functional renormalization group method (FRG). It is shown that the spectral function in the scalar channel shows a tachyonic behavior at finite momenta prior to the CP, which is interpreted to suggest that the assumed equilibrium state is unstable toward a stated with an inhomogeneous chiral condensate. This part is based on the following two papers by the same authors: T.Yokota, T.K. and K.~Morita, PTEP(2016) no.7, 073D01; arXiv:1707.05520 [hep-ph].

Daniel Frączek

Charakterystyka wieloskalowa niejednorodności materiałów wielofazowych oraz modelowanie ich właściwości efektywnych.

W niniejszej rozprawie przedstawiam i uogólniam metodę wieloskalowych deskryptorów entropowych zastosowaną do opisu stopnia przestrzennej niejednorodności materiałów wielofazowych. W wyniku otrzymano nowe fazowe deskryptory entropowe, które pozwalają na analizowanie ilościowo cech rozmieszczenia przestrzennego każdej z faz. Metodę entropową zastosowano do przeprowadzenia statystycznej rekonstrukcji trójwymiarowych materiałów wielofazowych korzystając z niepełnej informacji mikrostrukturalnej zawartej w pojedynczym przekroju i ujawnionej przez ogólny deskryptor entropowy. Rekonstrukcję przeprowadzono stosując różne metody, w tym nowe podejście prawa potęgowego z dwoma wykładnikami. W rozprawie przeanalizowano różne fizyczne podejścia do obliczania efektywnego przewodnictwa elektrycznego, koncentrując się na modelach sieciowych o niskich kosztach obliczeniowych z lub bez oddziaływania pomiędzy elementami fazy wysoko przewodzącej. Wyróżniającym się podejściem w przypadku braku oddziaływania jest prosty wariant przestrzennej grupy renormalizacyjnej. Metodę tę wykorzystano do poszukiwania możliwej relacji pomiędzy kontrolowanymi zmianami prototypowych mikrostruktur a ich efektywnym przewodnictwem elektrycznym

Dr Elizaveta Nazarova (Lomonosov Moscow State University)

Event-by-event Elliptic Flow Fluctuations in PbPb collisions at sqrt{s_NN} = 5.02 TeV with CMS detector

Event-by-event elliptic flow harmonic distributions p(v_2) are measured in PbPb collisions at sqrt{s_NN} = 5.02 TeV using the CMS detector for the integrated p_T range 0.3 < p_T < 3.0 GeV/c and pseudorapidity range |eta|<1.0 . In order to gain insight on the nature of the initial geometry fluctuations, cumulant flow harmonics are calculated from the moments of the v_2 probability distribution p(v_2). A fine-level splitting between the higher-order cumulants is observed. The skewness with respect to the reaction plane is estimated from the cumulants and found to be negative, which suggests a non-Gaussian nature for the initial-state fluctuations, as predicted by hydrodynamic models. These observations suggest a non-Gaussian nature of the initial-state fluctuations. Furthermore, assuming that the flow harmonics are linearly proportional to the initial-state eccentricities, the p(v_2) distributions are fitted using an elliptic power law parametrization to study the initial-state geometry fluctuations.

dr hab. Piotr Homola, IFJ PAN

Cosmic-Ray Extremely Distributed Observatory: new research possibilities in astroparticle physics

Cosmic-Ray Extremely Distributed Observatory (CREDO) enables a strategy for a global analysis of cosmic-ray data oriented on reaching the observational sensitivity to ensembles of particles of cosmic origin correlated in time: so-called cosmic-ray cascades. The CREDO approach defines a pioneer, although natural extension of a standard cosmic-ray research focused so far on single particles uncorrelated in time. Cosmic-ray cascades could be formed both within classical (e.g. products of photon-photon interactions) and exotic scenarios (e.g. result of decay of Super Heavy Dark Matter particles and subsequent interactions) and CREDO asks about the circumstances under which such phenomena can be observed. The spatial extent of some of cosmic-ray cascades that reach Earth might offer a unique signature detectable only with the cosmic-ray infrastructure taken as a global network of detectors, signature invisible for individual observatories. Thus the global approach to the detection of cosmic-ray cascades might be the only realistic option. The existing uncertainties about the available physics models at very high energies (photon structure, electrodynamics, space-time structure) as well as insufficient knowledge about the propagation mechanisms, makes one thinking on the CREDO research strategy like of a wide physics program rather than of a short-term project. A wide program requires a wide community of collaborators and that is why everybody is welcome to contribute to CREDO.

A public dissertation defense of mgr. Alexandr Dubinin

Thermodynamics of Mott dissociation of hadronic matter within a generalized Beth-Uhlenbeck approach

prof. Rene Brun, CERN

The NUONs model describing particles structures and their interactions

A new and non conventional model is proposed to describe particles properties. The fundamental unit is a NUON (neutrinos and electrons). All particles have 2 axial nuons around which N other nuons are rotating (eg N=3 for a muon, 4 for a pion, 32 for a Kaon, 64 for a proton). The geometry is dictated by pure Coulomb interactions and angular momentum. The masses of the particles is computed with high accuracy, as well as the magnetic moment and size. The proposed new proton structure has been tested in many configurations and different energies: -proton-proton elastic scattering from ISR to LHC energies -electron-proton and positron-proton deep inelastic scattering at HERA energies -proton-proton inelastic collisions with very accurate description of the kinematics and types of the generated particles and jets. The seminar will be given with the perspective and motivation of somebody who has spent most of his career in developing simulation or analysis tools for most experiments in High Energy or Nuclear physics and witnessed the development of the standard model and its success.

Dr Harri Niemi (Frankfurt University)

Transient relativistic fluid dynamics from the Boltzmann equation

A general derivation of relativistic fluid dynamics from the Boltzmann equation using the method of moments will be presented. The main difference between the presented approach and the traditional 14-moment approximation by Israel and Stewart is that we will not close the fluid-dynamical equations of motion by truncating the expansion of the distribution function. Instead, we keep all the terms in the moment expansion and truncate the exact equations of motion for the moments according to a systematic power counting scheme in Knudsen and Reynolds number. We show that the Boltzmann equation contains an infinite number of microscopic time scales and demonstrate that, in order to derive the fluid-dynamical equations of motion, it is essential to consider only the slowest of these time scales. We further test the validity of different approximations by comparing to the direct numerical solutions of the Boltzmann equation.

prof. Georg Wolschin, Univ. of Heidelberg

Spectroscopy in the quark-gluon plasma

Since the discovery of spectroscopy with solar light, the method has contributed to breakthroughs in physics. In the field of relativistic heavy-ion collisions, one may use it in an attempt to investigate the properties of the quark-gluon plasma that is being formed for very short times, and resembles the state of matter in the early universe. In particular, the spectroscopy of heavy mesons like charmonium and bottomonium is extremely sensitive to the properties of the surrounding quark-gluon medium, and is currently being used in experiments at the Large Hadron Collider. I present an overview of the physics goals, and a specific theoretical approach towards an interpretation of the results including recent predictions.

Prof. Georg Wolschin (University Heidelberg)

Bottomia physics at RHIC and LHC energies

The suppression of Y mesons in the hot quark-gluon medium (QGP) versus reduced feed-down is investigated at energies reached at the Relativistic Heavy Ion Collider RHIC and the Large Hadron Collider LHC. Our centrality- and p_T-dependent model encompasses screening, collisional damping and gluodissociation in the QGP. For the Y(1S) ground state it is in agreement with both STAR and CMS data provided the relativistic Doppler effect and the reduced feed-down from higher states are properly considered. At both energies, most of the Y(1S) suppression is found to be due to reduced feed-down, whereas most of the Y(2S) suppression is caused by hot-medium effects. The importance of the latter increases with energy. The p_T-dependence is flat due to the relativistic Doppler effect and reduced feed-down. Results for PbPb at 5.02 TeV are predicted and compared with recent LHC run 2 preliminary data.

Remigiusz Durka

Topological insulators from the Maxwell algebra

The subject of the talk will concern a recent work of D. Palumbo https://arxiv.org/abs/1610.04734. It introduces interesting model of three dimensional topological insulators in the presence of the electromagnetic field, which results from the Chern-Simons theory with the gauge connection that takes values in the Maxwell algebra. The final action written in terms of the dreibein, spin connection and electromagnetic gauge potential leads to a description of the Hall conductance, the torsional Hall viscosity, and novel non-minimal coupling between the abelian gauge field and curved background, which resemble the relativistic version of the Wen-Zee term.

Pok Man Lo

S-matrix approach to hadron gas, part II

In this talk, we shall discuss how the S-matrix formalism can be applied to describe the system of hadrons in heavy ion collisions. The approach provides a consistent way to incorporate attractive and repulsive forces between hadrons. Using the input of empirical phase shifts from hadron scattering experiments, the important physics of resonance widths, coupling strengths and unitary constraints are naturally incorporated, beyond the capability of the standard Breit-Wigner formulation. In particular, we show how the proper treatment of the resonance widths can substantially modify the soft part of the pion momentum spectra. Lastly, we shall attempt to extend the approach to include N-body scatterings. For this a generalization of the two-body phase shift will be considered. As a numerical example we compute the generalized phase shifts of some three- and four-body processes for an interacting gas of pions.

prof. dr hab. Piotr Jaranowski, UwB

Analytical relativity and the first direct detections of gravitational waves

After a short update on the first direct detections of gravitational waves being made by LIGO detectors, the crucial role of analytical relativity results for the successful detections and estimation of parameters of gravitational-wave signals coming from coalescing black-hole binaries will be explained. The adjective "analytical" means here methods that rely on solving explicit (that is analytically given) ordinary differential equations, contrary to full numerical relativity simulations. Among numerous analytical relativity results the emphasis will be placed on post-⁠Newtonian approximations and on effective one-⁠body approach to relativistic two-⁠body problem.

Pok Man Lo

S-matrix approach to hadron gas

In this talk, we shall discuss how the S-matrix formalism can be applied to describe the system of hadrons in heavy ion collisions. The approach provides a consistent way to incorporate attractive and repulsive forces between hadrons. Using the input of empirical phase shifts from hadron scattering experiments, the important physics of resonance widths, coupling strengths and unitary constraints are naturally incorporated, beyond the capability of the standard Breit-Wigner formulation. In particular, we show how the proper treatment of the resonance widths can substantially modify the soft part of the pion momentum spectra. Lastly, we shall attempt to extend the approach to include N-body scatterings. For this a generalization of the two-body phase shift will be considered. As a numerical example we compute the generalized phase shifts of some three- and four-body processes for an interacting gas of pions.

prof. dr hab. Robert Alicki, UG

Interaction of a quantum field with a rotating heat bath

The linear coupling of a rotating heat bath to a quantum field is studied in the framework of the Markovian master equation for the field's non-unitary time evolution. The bath's rotation induces population inversion for the field's low-energy modes. For bosons, this leads to superradiance, an irreversible process in which some of the bath's kinetic energy is extracted by spontaneous and stimulated emission. We find the energy and entropy balance for such systems and apply our results to the theory of black hole radiation. The talk is based on the joint paper with Alejandro Jenkins http://arxiv.org/abs/1702.06231

Eduardo Saúl Sala

Production and radiative decay of heavy neutrinos at the Booster Neutrino Beam

The MiniBooNE experiment reported results from the analysis of $nu_e$ and $overline{nu}_e$ appearance searches, which showed an excess of signal-like events at low reconstructed neutrino energies with respect to the expected background. A proposed explanation for this anomaly is based on the existence of a heavy ($sim 50$~MeV) sterile neutrino. These $nu_h$ would be produced by $nu_mu$ electromagnetic interactions, through a transition magnetic dipole moment, and by neutral current interactions on nuclei. A fraction of them decays radiatively inside the detector. The emitted photons are misidentified as electrons or positrons in MiniBooNE. We have investigated the $nu_h$ production by coherent and incoherent electroweak interactions on CH$_2$ and Ar targets, present in the MiniBooNE and the Short Baseline Neutrino (SBN) detectors (MicroBooNE, SBND and ICARUS) at Fermilab. Following the $nu_h$ propagation inside the detector we are able to obtain the energy and angular distributions of the final photons. Within the valid range of model parameters, we have obtained the best-fit parameters to describe the MiniBooNE excess of events. To further investigate this scenario, we have obtained the expected the signal at the SBN detectors. The distinctive shape and total number of photon events from this mechanism makes its experimental investigation feasible.

Mr. Aleksandr Dubinin, IFT

Thermodynamics of Mott dissociation of hadronic matter within a generalized Beth-⁠Uhlenbeck approach

We present an effective model for low-energy QCD thermodynamics which provides a microscopic interpretation of the transition from a gas of hadron resonances to the quark-gluon plasma by Mott dissociation of hadrons and compares results with data from lattice QCD simulations.We consider the thermodynamics of the Polyakov-loop extended Nambu–Jona-Lasinio (PNJL) model within the self consistent approximation scheme of the Phi-derivable approach.This allows us to obtain the Generalized Beth-Uhlenbeck (GBU) equation of state.Our approach goes beyond the mean-field description of quark matter by taking into account hadronic correlations as well as their backreaction on the propagator of constituents.The next step in our work is to include more hadronic degrees of freedom than just the low-lying pseudoscalar mesons.For that purpose,we discuss a model for the generic behavior of hadron phase shifts at finite temperature which shares basic features with recent developments within the PNJL model for correlations in quark matter.This model is defined by the temperature dependence of hadron masses and widths as well as for their corresponding continuum thresholds.We also discuss the occurrence of an anomalous mode for mesons composed of quarks with unequal masses which is particularly pronounced for positive kaon (K+) and kappa states at finite densities.It may serve as a possible mechanism to explain the "horn effect" for the K+/pi+ ratio in heavy-ion collisions.

Dr Jakub Jankowski (IFT)

Real time dynamics, phase transitions and holography

Recent results concerning the dynamics of holographic systems exhibiting various types of phase transformations will be reviewed - with a particular focus on first order transitions. The existence of the spinodal region will be demonstrated within linear and nonlinear response theory. The applicability of hydrodynamics in the critical region of the phase diagram would be discussed.

dr Callum Wilkinson (remotely)

A bit of a NUISANCE: constraining neutrino cross section systematics

Reducing neutrino cross-section systematics will be essential to reach the sensitivity goals of current and future neutrino oscillation experiments. The NUISANCE framework has been developed to specifically address this problem by providing a powerful generator tuning framework capable of making comparisons between multiple generators and a broad range of existing neutrino cross-section data. In this talk I will review the framework itself, before discussing its use within T2K to develop a comprehensive set of model uncertainties with current data. I will also highlight the limitations to this sort of approach.

prof. dr Kei Kotake, Fukuoka Univ.

Exploding stars with supercomputers and multi-messenger probes of the supernova engine

A massive star of at least 10 times the mass of our sun ends its life in the most energetic explosion of the modern universe,known as supernova. The nearest one,SN1987A, occurred in the Large Magellanic cloud on February 23rd 1987,where cosmic neutrinos were detected for the first time.It was awarded the Nobel Prize in 2002 which opened up the new field of neutrino astronomy.Supernovae are also at the frontier of yet another novel epoch, the age of gravitational-wave astronomy,with the first detection of gravitational waves from binary black hole mergers announced by the LIGO collaboration in 2016.The next generation of detectors is expected to yield gravitational waves also from supernovae.Significant progress has been made in supernova theory during the past three decades,aiming at the fundamental question:What is the mechanism that drives the explosion?In order to unambiguously address this question,perform large-scale numerical studies are required.Using some of the world-biggest supercomputing facilities,supernova modelers are now reporting on some success.In my talk I will discuss the state-of-the-art of this field and illuminate future directions of fundamental supernova research,which relate to multi-messengers observation: the simultaneous analysis of neutrino signal,as well as gravitational and electromagnetic waves.It is indispensable that these signatures will reveal the secrets of the central supernova engine,that is otherwise hidden deep inside a massive star.

Tomasz Golan

Markdown, Pandoc, and other tools for lazy people

During the seminar I will demonstrate some useful tools for making web pages, presentations, or PDF documents in an easy way by using Markdown markup language. Markdown syntax will be introduced, followed by basic examples of using Pandoc to convert Markdown files to HTML, LaTeX (including Beamer presentations) or directly to PDF. Then, I will present selected applications using Markdown as source files.

prof. dr, dr h.c. Helmut Satz, Univ. of Bielefeld

Thermal Multiparticle Production as Hawking-Unruh Radiation

High energy collisions lead to multihadron production. The abundances of the produced hadrons are in accord with emission by a thermal source of a universal temperature, even when the number of hadrons hardly justifies a thermal description. We show that tunneling through the confinement horizon justifies thermal behavior as the QCD analog of Hawking-Unruh radiation.

Prof. I. Dadic (1 Rudjer Bovskovi'c Institute, Zagreb, Croatia)

Causality and Renormalization in Finite-Time-Path --- Out-of-Equilibrium $phi^3$ QFT

We use the retarded/advanced basis of out-of-equilibrium Green functions. We use the dimensional regularization method and find the correspondence of diverging contributions in the Feynman diagrams and their counterparts in R/A basis.

prof. dr hab. Marek Kuś, CFT PAN

Beyond quantum mechanics

Quantum mechanics is quite resistant to “small improvements". Variousattempts to replace it with a corrected (vis. “better") theory seem to run into troublesproducing results contradicting with experimentally established. Abandoning thus an elusive and hardly desirable idea of improving quantum mechanics, or replacing it with something “better”, it is tempting to understandhow itdifferentiates from other “possible theories” fulfillingsome general principles (like e.g. causality). I will show how to approach the problem from the logical point of view, exhibiting the exceptional position of quantum mechanics in comparison with classical mechanics and other possible causal theories with respect to such fundamental features as uncertainty relations and the existence of entangled states. Both properties are extremely important from the point of view of“ontological promises" offered by quantum mechanics. The quantum world is not only epistemically random (any apparent random dynamical behavior is caused by lack of knowledge of exact values of observables, like in classical physics), but intrinsically (ontologically) probabilistic.

prof. dr hab. inż. Arkadiusz Wójs , PWr

Fractional skyrmions in quantum Hall systems

The talk will review the physics of skyrmions formed in ferromagnetic quantum Hall states of 2D electrons in a high magnetic field. They carry electric charge, angular momentum, and massive spin. Their emergence as low energy charged quasiparticles in a ferromagnetic ground state causes depolarization and supports spin-flip excitations with energies below the single-electron spin splitting which can be probed by Raman spectroscopy. Skyrmions have also been predicted in ferromagnetic fractional quantum Hall (FQH) systems, such as Laughlin incompressible liquid at the Landau level filling factor ν=1/3. Understanding of the FQH effect involves exotic emergent topological particles, such as fractionally charged quasiparticles, composite fermions (CFs), nonabelian anyons, or Majorana fermions. In particular, incompressibility and the excitation spectrum of the many known FQH ground states is underlied by the formation of essentially free CFs from strongly correlated electrons – through binding of pairs of vortices of the many-electron wave-function as a result of Coulomb interaction in a degenerate Landau level. As fractional quantum Hall states of electrons correspond to integral quantum Hall states of CFs, fractional skyrmions emerge as topological spin textures in the CF ferromagnets. Owing to different form and reduced energy of effective CF interaction, the hypothetical fractional skyrmions are fragile objects, easily suppressed by even fairly weak Zeeman effect.

Andrzej Pękalski / Zbigniew Koza

Dziwna dyfuzja

Wewnętrzne seminarium robocze poświęcone najnowszym wynikom w modelu prof. Pękalskiego Uwaga: zmiana sali 435

dr hab. Adam Sawicki (CFT, Warszawa)

Universal quantum gates

I will consider the problem of deciding if a finite set of quantum one-qudit gates is universal, i.e if the generated group is either the special unitary or the special orthogonal group. To every gate I will assign its image under the adjoint representation. The necessary condition for the universality is that the only matrices that commute with all the adjoint representation matrices are proportional to the identity. If in addition there is an element in the considered group whose Hilbert-Schmidt distance from the centre is smaller than 1/sqrt{2}, then the set of gates is universal. Using these I will present a simple algorithm that allows deciding the universality of any set of d-dimensional gates in a finite number of steps. Moreover, I will formulate the general classification theorem. This is a joint work with Katarzyna Karnas.

prof. dr hab. David Blaschke, IFT UWr

50 years discovery of pulsars – precise probes of space, time and matter under extreme conditions

I give an introduction to the fantastic properties of pulsars, cosmic “lighthouses” that were discovered in 1967 by Jocelyn Bell, a young PhD student at that time, by studying signals obtained from a newly constructed radio telescope. Soon after this discovery it became clear that these regular radio signals came from fastly rotating neutron stars, objects that were anticipated by Lev Landau even before the discovery of the neutron in 1932 and described as possible remnants of supernova explosions by Baade and Zwicky in 1934. Meanwhile more than 2500 pulsars are known and in this seminar I will describe some of them which have most remarkable properties that allow us to measure the structure of space-time in our cosmic neighborhood and to better understand the matter under extreme conditions of high densities and strong fields in their interiors. Those conditions we shall recreate for short moments of time in heavy-ion collision experiments of the third generation which are under construction at NICA in Dubna and FAIR in Darmstadt.

Konstantin Maslov, NRNU (MEPhI) Moscow

A method of stiffening the relativistic mean-field (RMF) equation of state and its application to the description of neutron stars

It will be shown a way to make a given RMF equation of state for hadronic matter stiffer at high densities, while leaving it unchanged at lower densities. This method can be used to change the stiffness of either both isospin symmetric and asymmetric parts or only asymmetric part of the equation of state (EoS) in the RMF framework with field-dependent hadron masses and couplings. This allows to construct realistic phenomenological RMF models which are flexible enough to pass many experimental constraints.

Tomasz Golan

Markdown, Pandoc, and other tools for lazy people

During the seminar I will demonstrate some useful tools for making web pages, presentations, or PDF documents in an easy way by using Markdown markup language. Markdown syntax will be introduced, followed by basic examples of using Pandoc to convert Markdown files to HTML, LaTeX (including Beamer presentations) or directly to PDF. Then, I will present selected applications using Markdown as source files.

Dariusz Prorok

Centrality dependence of freeze-out temperature fluctuations in Pb-Pb collisions at the LHC

Many data in the High Energy Physics are, in fact, sample means. It is shown that when this exact meaning of the data is taken into account and the most weakly bound states are removed from the hadron resonance gas, the whole spectra of pions, kaons and protons measured at midrapidity in Pb-Pb collisions at $sqrt{s_{NN}} = 2.76$ TeV can be fitted simultaneously. The invariant distributions are predicted with the help of the single-freeze-out model in the chemical equilibrium framework. The method is applied to the measurements in centrality bins of Pb-Pb collisions and gives acceptable fits for all but peripheral bins. The comparison with the results obtained in the framework of the original single-freeze-out model is also presented.

prof. dr hab. Włodzimierz Stefanowicz, IF UO

Fractional quantum mechanics and confining potentials for Levy flights.

Levy flight is non-Gaussian stochastic process having probability density function (PDF) slowly (as compared to Gaussian) decaying at infinities. This yields the divergent second moments of corresponding PDF. To make Levy flights be usable in real physical systems, we need to make their higher moments existent. For that suitably tailored (dictated by specific physical problem) external potentials are used. Here we discuss different confining mechanisms, met in real physical systems. One of them is so-called fractional quantum mechanics, when ordinary Laplacian in the Schrodinger equation is substituted by the fractional derivative. We discuss the method of solution of fractional quantum mechanical problems.

Prof. L.Turko, Dr. P.Huovinen, Mr. A.Dubinin

Three generations view on quark matter

Based on personal attendance in the last Quark Matter Conference – Chicago 2017 – review of recent progress/digress of research and understanding in the field of dense hadronic matter will be presented.

dr Adam Smetana (Institute of Experimental and Applied Physics, CTU in Prague)

Role of neutrinos in the electroweak symmetry breaking

The condensation of known fermions is an appealing idea for explaining the electroweak symmetry breaking (EWSB) already since early eighties. It is natural to treat the top-quark condensate as the only non-negligible source of EWSB as the top quark dominates the fermion mass spectrum. However many realistic models of this kind have failed in reproducing the correct spectrum of masses of the top-quark and of the W, Z and Higgs bosons. We study the role of neutrino condensation. If a seesaw mechanism applies for the neutrino masses, the Dirac mass and the corresponding neutrino condensate may be significantly strong source of the electroweak symmetry breaking comparable to that of top-quark. Within the simplistic model we show that the number of right-handed neutrinos needed for meeting phenomenological requirements is very large, O(100).

Grzegorz Kondrat

Prosty model dyfuzji i kilka pytań - ciąg dalszy, czyli m.in. kilka odpowiedzi

N/A Uwaga: zmiana sali 435

prof. dr hab. Tomasz Dietl, IF PAN

Spin dynamics in magnetic nanostructures: quantum vs. semiclassical approach

A number of quantum models and corresponding numerical diagonalization procedures have been proposed to describe spin dephasing of an electron injected to a quantum dot containing typically 103 to 106 nuclear magnetic moments. These theoretical studies have revealed many unanticipated behaviors assigned to the quantum nature of the bath spins [1]. A question then arises whether it is justified to describe spin dynamics of spintronic devices (having now diameters down to 11 nm) us¬ing semiclassical approaches, in which injection of electron spins is treated quantum mechanically but spin dynamics is described by using the essentially classical Landau-Lifshitz-Gilbert equation. In our work [2] we provide a formalism suitable to describe experimental results in a wide parameter space, allowing also to benchmark various implementations of quantum theory. Our approach to this central spin problem is also suitable for examining dissipation-less dynamics of confined superconductors and ultra-cold gases. [1] A. Faribault and D. Schuricht, Phys. Rev. Lett. 110, 040405 (2013), and references therein. [2] T. Dietl, Phys. Rev. B 91, 125204 (2015).

prof. Andrzej Pękalski

Prosty model dyfuzji i kilka pytań

Krzysztof Graczyk

Remarks on Magnetic Moment of Proton

[PLEASE NOTE NEW DATE OF THE SEMINAR] I will review the calculations of the QED corrections to the electromagnetic moment of the proton. The attention will be paid on the technical details of the derivation.

prof. dr hab. Krzysztof A. Meissner, UW

Conformal anomalies

We argue that the presence of conformal anomalies in gravitational theories can lead to observable modifications to Einstein’s equations via the induced anomalous effective actions, whose non-localities can overwhelm the smallness of the Planck scale. The fact that no such effects have been seen imposes strong restrictions on the field content of possible extensions of Einstein’s theory: all viable theories should have vanishing conformal anomalies. It turns out that a complete cancellation of conformal anomalies in D = 4 can only be achieved for N-extended supergravity multiplets with N > 4, as well as for M theory compactified to four dimensions.

Grzegorz Kondrat

Perkolacja jest zawsze, czyli dowód pewnego twierdzenia

Na seminarium zostanie przedstawione uzasadnienie faktu (skądinąd poddawanego w wątpliwość), że perkolacja w układzie igieł na sieci występuje zawsze (jak sie poczeka dostatecznie długo).

prof. dr hab. Dariusz Kaczorowski, INTiBS PAN

Rare-earth based half-Heusler phases: from thermoelectrics to topological insulators

Half-Heusler (HH) phases of the general compositions XYZ, where X and Y stand for d- or f-electron transition metals and Z denotes a p-element, form a large family of materials characterized by a variety of different physical and chemical properties, useful in many applications, e.g. in spintronics and green energy harvesting. Due to theirremarkable multifunctionality, easily tunable by small modifications in composition, morphology or external factors,HHphases are commonly called „materials with properties on request”. Recently, new interest in studying rare-earth bearing HHphases was ignited by theoretical predictions of the formation in some of them of nontrivial topological surface states, which results in various unconventional physical phenomena, basically driven by Rashba-typespin-orbit interaction. The combination of non-trivial topology, superconductivity and long-range magnetism makes the HHphaseshighly interesting in regard to novel functionalities, advantageous in quantum computing and/or magnetoelectronics. In this talk, we shall briefly review our own contribution to the blooming subject of rare-earth based HHcompounds. The main focus will be put on (i) their performance as promising thermoelectric materials, as well as (ii) the emergence of superconductivity and long-range magnetism in a few phases considered as putative topological insulators or Dirac/Weyl semimetals.

Dr Pok Man Lo (IFT)

CANCELLED: S-matrix approach to quantum virial expansion

THIS SEMINAR IS POSTPONED ON A LATER TIME In this talk, we discuss the application of S-mat rix formalism to study higher virial coefficients for a quantum-mechanical system of hadrons. The virial expansion provides a convenient way to parametrize the equation of state of a many-body system. It expresses the partition function and various thermodynamic functions as a power series in the particle density. For a classical system (e.g. the van der Waals non-ideal gas), the coefficients of the expansion can be computed directly from the Hamiltonian using the standard Mayer cluster expansion. The quantum version of such expansion has been formulated by Dashen, Ma and Bernstein within the framework of S-matrix. This allows the exact calculation of the 2nd virial coefficient from the knowledge of phase shift. We shall review briefly how this formalism can be applied to describe system of hadrons in heavy ion collisions. Using the input of empirical phase shifts from hadron scattering experiments, the important physics of resonance widths, coupling strengths and unitary constraints are naturally incorporated, beyond the capability of the standard Breit-Wigner formulation. The extension to third (and higher) virial coefficients is more challenging. Here, we attempt a generalization of two-body phase shift and define an analogous physical quantity suitable for discussing N-body scatterings. We shall examine such generalized phase shift in details for a gas of pions.

Joanna Sobczyk

A role of spectral functions in lepton-nucleus interaction

In this talk I will sketch the formalism developed by E. Oset and F. de Cordoba in which a semiphenomenological nucleon's spectral function is obtained. Then we will see how it is included into a model of lepton-nucleus interaction. At the end (if time permits), I will analyze how to include the RPA effects on top of the spectral function.

prof. dr hab. Andrzej Drzewiński, UZ

Exotic Matter, pastries and the Nobel Prize in physics

It is said that matter can exist in one of three states, as a gas, liquid or solid, and the passage from one state to another occurs through a process called phase transition. But when one considers the matter formed in the shape of thin layers or wires, and strongly cooled, there is a whole collection of exotic states: superfluids, superconductors or magnets with the hidden order. In order to explain these unusual phenomena David Thouless, Duncan Haldane and Michael Kosterlitz have adapted to physics interesting methods belonging to the area of mathematics called topology. The object of its interest is the property of bodies that remain unchanged even under the deformation of objects. We can bend and squeeze them but tearing into parts or gluing is not permitted! The most interesting is that the properties of abstract shapes can be exploited to describe how very cold atoms and electrons behave. For example, they allowed physicists to show that in low temperatures certain properties of a very thin sheet that can conduct electricity should change in integer steps which is typical for properties rooted in topology. Other aspects of topology used to describe collections of many particles are still under development and widely studied.

dr Artur R. Pietrykowski (IFT-Wrocław; JINR-Dubna)

Irregular blocks, 4d gauge theories and Hill's equation

The Alday-Gaiotto-Tachikawa (AGT) correspondence relates two-dimensional Conformal Field Theory (2dCFT) on $n$-punctured Riemann surface with four-dimensional $mathcal{N}=2$ superconformal field theories (4d-SCFT). In particular, 4d $mathcal{N}=2$ super Yang-Mills theory with $N_{f}=4$ flavors on certain background corresponds to 2dCFT on four-punctured Riemann sphere. The extension of this correspondence to $mathcal{N}=2$ nonconformal 4dSCFT revealed a completely new object in 2dCFT -- the irregular vectors and the irregular conformal blocks. On the other hand there is a relationship between a certain limit of $mathcal{N}=2$ 4dSCFT and Quantum Integrable Systems (QIS) (the so-called Bethe/Gauge correspondence). It is, therefore, possible to exploit the nonconformal AGT relation to derive the similar connection between 2dCFT and the Quantum Integrable Systems. The talk is devoted to show the latter in specific examples, namely, for number of flavors $N_{f}=0,1,2$. The case of arbitrary number of flavors $N_{f}>2$ will be also discussed.

Members and fans of EPTh division

"Quo Vadis?" Where have we been, what have we done in 2016 and where will we go in 2017?

Group members report on their breakthrough ideas, most remarkable visits, publications and events organisation accomplished in 2016. They also mention what could not yet be achieved and what will be on the agenda in 2017. Rules: no more than 10' pp. Potential speakers/performers are kindly asked to contact LT and report about their readiness to present their microseminar.

Members and fans of EPTh division

"Quo Vadis?" Where have we been, what have we done in 2016 and where will we go in 2017?

Group members report on their breakthrough ideas, most remarkable visits, publications and events organisation accomplished in 2016. They also mention what could not yet be achieved and what will be on the agenda in 2017. Rules: no more than 10' pp. Potential speakers/performers are kindly asked to contact LT and report about their readiness to present their microseminar.

Beata Kowal

Single pion production and symbolic computation

In the first part of my seminar I'll talk about single pion production in neutrino-nucleon interaction. Then I'll make an introduction to FORM - the programming language to symbolic computation, I'll present examples of programs written in FORM and I'll show how I apply it to my work.

prof. dr hab. Paweł Machnikowski, PWr

Culomb interactions in quantum dots

After a brief introduction into the most essential physical properties of self-assembled quantum dots (QDs) I will discuss how Coulomb interactions between carriers confined in QDs can be described and classified on the mesoscopic level. Starting from the envelope function approximation, which is the most commonly used theoretical method for the description of carrier states in this kind of semiconductor nanostructures, I will describe the general framework of mesoscopic expansion, which is a natural tool for the theoretical analysis of Coulomb couplings. Within this framework, I will discuss recent results concerning the manifestation of Coulomb effects in differential transmission spectra, the Förster transfer of excitation between the QDs, Coulomb-induced transitions between states with different numbers of electrons and holes (Auger relaxation and impact ionization), and two-particle resonances in coupled quantum dots.

Dr Marcus Bluhm (North Carolina State U.)

Properties of strongly coupled quantum fluids

Strongly coupled quantum systems are realized in nature in various forms, reaching from compact stellar objects, over tiny droplets of hot Quark-Gluon Plasma, to ultra-cold atomic Fermi and Bose gases. These systems share some interesting features despite their apparent differences in size, temperature, density or field strengths. This talk will focus on the Quark-Gluon Plasma and ultra-cold Fermi gases, discuss the observed similarity in their transport behavior, notably their perfect fluidity, and present some recent developments toward a better understanding of both strongly coupled quantum fluids.

prof. Pavel Stovicek (Praha)

On quantum mechanics on multiply connected configuration spaces, with examples.

A construction of the heat kernel (or the propagator) for Hamiltonians on multiply connected configuration spaces, originally due to L. Schulman, is described. Its connection to the Bloch decomposition of symmetric Hamiltonians is discussed. The discussion is completed with some old and new examples.

prof. Marek A. Abramowicz, Göteborg University

Ringdowns and Afterglows czyli Podzwonne i Poświaty

I will discuss how LIGO/Virgo obserwations of the wave fronts in the last moments of a gravitational wave event (ringdowns), and observations of electrodynamical follow-up of these events (afterglows) may help to constrain (reject) some models of quantum alternatives to black holes.

K. Morita (Yukawa Institute of Theoretical Physics, Kyoto, Japan)

Omega-proton correlation in heavy ion collisions

The two-particle momentum correlation between the proton (p) and the Omega-baryon (Ω) in high-energy heavy ion collisions is studied to unravel the possible spin-2, S=-3, pΩ-dibaryon recently suggested by lattice QCD simulations.

Nils Van Dessel and Tom Van Cuyck

Neutrino work in Ghent group

Two complementary presentations on neutrino work in Ghent: Nils Van Dessel : Quasi-Elastic neutrino-nucleus scattering with applications to Argon Tom Van Cuyck : Short-range correlations and meson-exchange currents in neutrino-nucleus scattering

dr hab. Mirosław R. Dudek, prof. UZ

Shape memory in magneto-auxetics

A novel class of metamaterials having magnetic insertions embedded within a non-magnetic auxetic matrix is under discussion. It is shown that such systems can exhibit a series of anomalous properties which include tunable Poisson’s ratio as well as ferromagnetic and shape memory behaviour. Recently, the magnetocaloric effect (MCE) exhibited by magneto-auxetic systems in the vicinity of room temperature was discussed. Some features, like the system negative thermal expansion property for shape recovering was presented.

Mateusz Cierniak (IFT)

The Munczek-Nemirovsky model in different metrics.

The Munczek-Nemirovsky (MN) model is defined by a set of truncations which simplify the Dyson-Schwinger equation (DSE) of a quark propagator to a form that can be solved analytically. In general the DSE is a self-similar equation that is usually solved by numerical iteration. Unlike the analytical approach, the iterative method produces fractal patterns and naturally drives the MN model's quark mass gap into a low mass state in analogy (but still with qualitative difference) to asymptotic freedom. My initial calculations were done with respect to the Euclidean QCD generating functional and in this talk I compare them to the solutions obtained in the Minkowski metric.

prof. Robert Olkiewicz

Odwzorowania podwójnie stochastyczne na macierzach 3x3 - kontynuacja

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Prof. Andre Peshier (University of Cape Town, SA)

Tracing the QCD pressure

Being interested in how a strongly coupled system approaches asymptotic freedom, we re-examine existing precision lattice QCD results for thermodynamic properties of the gluon plasma in a large temperature range. We discuss and thoroughly test the applicability of perturbative results, on which grounds we then infer that the pressure and other bulk properties approach the free limit somewhat slower than previously thought, and we revise the value of the first non-perturbative coefficient in the weak-coupling expansion.

Dyrekcja IFT

Spotkanie Pracowników IFT

Dyrekcja IFT zaprasza wszystkich pracowników naukowo-dydaktycznych Instytutu na spotkanie w dniu 18 listopada br. około godz. 13.00 (po posiedzeniu Rady Instytutu). Celem spotkania będzie: 1. wręczenie nagród Rektora UWr za działalność naukową, organizacyjną i dydaktyczną w 2015 r. 2. szkolenie na temat wypełniania wniosków grantowych do NCN prowadzone przez osoby uczestniczące w przeszłości w pracach paneli oceniających. Przewidywany czas trwania ok. 60 minut.

Tomasz Golan

The review of the MINERvA experiment

MINERvA is a neutrino cross section experiment located at Fermilab. A high-intensity beam is used to study neutrino reactions with five different nuclei. It gives an unique opportunity to study nuclear effects in neutrino-nuclei interactions. The structure of the MINERvA detector and the efforts to estimate a neutrino beam will be presented as an introduction to the second part of the talk - the review of MINERvA measurements.

prof. Robert Olkiewicz

Odwzorowania podwójnie stochastyczne na macierzach 3x3

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Jan Sobczyk

Challenges in neutrino cross sections

Przedstawiony zostanie (autorski) wybór najważniejszych problemów związanych z obliczeniami/pomiarami neutrinowych przekrojów czynnych na oddziaływanie z nukleonami i jądrami atomowymi.

prof. dr hab. inż. Arkadiusz Wójs , PWr

Fractional skyrmions in quantum Hall systems

Seminarium profesora Arkadiusza Wójsa zostało przeniesione na późniejszy termin z powodu ceremonii pogrzebowych Profesora Zygmunta Galasiewicza, które zostały zaplanowane na dzień 4 listopada, początek ceremonii o godzinie 13.00.

dr Chihiro Sasaki, prof. UWr

Probing the QCD phase transition with fluctuations and correlations

Modifications in magnitude of fluctuations for different observables are an excellent probe of a phase transition or its remnant. In particular, fluctuations related to conserved charges carried by light and strange quarks play an important role to identify the QCD chiral crossover and deconfinement properties. We give a brief overview of hot/⁠dense QCD and the phase structure.

dr hab. Lech Jakóbczyk

Jak bardzo qutrity różnią się od qubitów?

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mgr Kajetan Niewczas

The contribution of two-particle–two-hole final states in electron-nucleus scattering

As an introduction to the topic, the detailed calculation of the electron nucleus cross section will be presented. The analysis will be performed within three approximations: the impulse approximation, the plane wave impulse approximation and the relativistic plane wave impulse approximation [Nucl.Phys. A632 (1998) 323-362]. This part of the seminar will be finished with a discussion about two-body current interactions and the factorization issues therein. The second part of the seminar will be devoted to the theoretical framework describing the 2p2h final states contribution in the extended factorization ansatz [Phys.Rev. C92 (2015) 024602].

dr Armen Sedrakian

Phase diagram and BCS-BEC crossover in polarized fermionic quantum systems

I will discuss the physics of a broad class of systems, which include ultra-cold gases, nuclear systems, QCD matter at finite $mu$, under spin or isospin polarization. This will include the phase diagram of homogeneous and inhomogeneous superfluid phases, BCS-BEC crossovers, and critical points. The current status of experimental searches for the phase of the fermionic matter with ultra-cold gases and in neutron stars will be discussed.

Dr Aneta Wojnar (IFT)

Equilibrium and stability of relativistic stars in extended theories of gravity

Now, there is the correct day of this seminar - FRIDAY as usual! :-) The static, spherically symmetric equilibrium configurations in extended theories of gravity (ETGs) is studied. We show that the stellar structure in ETGs can be recast in a very generic form: i.e. one gets the generalization of the Tolman-Oppenheimer-Volkoff equations. A stability analysis is also performed with special focus on the particular example of scalar-tensor gravity.

dr Dmitry Zhuridov (University of Silesia)

Composite neutrinos and baryogenesis identity

Excited leptons that share the lepton numbers with the Standard Model leptons, but have larger masses, are predicted in the theories of compositeness. I will discuss the bounds on the excited neutrino masses that are still allowed to be of order 1 TeV. Then I will introduce possible generation of the baryon asymmetry of the universe using these new particles. The discussed baryogenesis does not contradict to the small masses of the observable neutrinos and the proton stability.

dr hab. Krzysztof Graczyk

Bayesian Inference in Investigation of Lepton-Nucleon Interactions

The subjective review of the Bayesian methods adapted to study the lepton-nucleon scattering will be presented. The main attention will be focused on the neural network approach and its adaptation for study the proton radius problem and two-photon exchange physics (ep scattering). Bayesian methods allow one to control the impact of initial model assumptions on the results of the investigation, to classify quantitatively various physical hypothesis.

Prof. dr hab. David Blaschke (IFT)

Mott dissociation of pions and kaons in hot, dense quark matter

The Beth-Uhlenbeck approach to the description of meson bound state formation and dissociation in hot dense quark matter is generalized to the case of 2+1 flavors on the basis of the PNJL model. One unexpected finding is the appearance of an anomalous K+ bound state in medium which appears as a good candidate for explaining the "horn" effect for the K+/pi+ ratio as observed in the energy scan by the NA49 experiment and confirmed by STAR.

Alaksiej Kachanovich (IFT) - ON THURSDAY!

Gluon background field approximation to Yang-Mills thermodynamics

We give an introduction to the Sasaki-Redlich model for Yang-Mills thermodynamics in the background field approximation. We show that in the second order with respect to gluon field fluctuations the partition function depends only on the traced Polyakov loop Phi. We solve the gap equation for Phi as a function of the temperature and compare the result with lattice QCD simulations. We discuss next steps beyond the Gaussian approximation which lead, e.g., to a temperature dependent gluon mass.

Prof. Dietmar Ebert, Humboldt-University, Berlin

Phase transitions in hexagonal, graphen-like lattice sheets and nanotubes

This talk considers a class of (2+1)D schematic models with four-fermion interactions that are effectively used in studying condensed-matter systems with planar structure, and especially graphene. Symmetry breaking in these models occurs due to a possible appearance of condensates. Condensates as well as fermion-antifermion exciton bound states are calculated. Moreover, nanotubes with corresponding boundary conditions are considered and their relation with the effect of an applied external magnetic field is discussed. To study phase transitions, the effective potential for the nanotube model including effects of finite temperature, density and an external magnetic field is calculated. Finally, the phase structure of the nanotube model under the influence of the Aharonov-Bohm effect is considered.

Niels-Uwe Friedrich Bastian (IFT)

Density functional theory for effective QCD equation of state

We introduce a thermodynamic consistent formulation to describe relativistic equations of state based on arbitrary density functionals. Based on this we investigate the possibility of a van-der-Waals like phase transition by introducing a density dependent excluded volume, to construct flexible QCD EOS with critical endpoint. Authors: Niels-Uwe Bastian, Mark Kaltenborn

Dr Aleksei Ivanytskyi (Bogoliubov Institute for Theoretical Physics, Kiev, Ukraine)

A novel equation of state for nuclear and hadronic matter with induced surface tension

Short range particle repulsion is proven to be rather important property of the hadronic and nuclear matter equation of state. A novel approach is presented, based on the virial expansion for a multicomponent system with hard core repulsion. A contribution of surface tension induced by particle interaction is a principally new element of that approach. Applications of this equation of state to the description of hadronic multiplicities measured in A+A collisions, the nuclear matter phase diagram and to modelling neutron star interiors are discussed.

Seminarium odwołane z powodu wycofania się referenta

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mgr Marek Miller

Positive maps and the problem of entanglement detection

Positive maps on operator algebras, specifically on matrix algebras, are extremely useful mathematical tools in the study of entanglement in quantum information theory. A surprising correspondence between positive maps and the so-called entanglement witnesses, i.e. observables that in principle could facilitate detecting entanglement of a quantum state, was established in 1990s and since then, it has been the starting point in any attempt to solve the non-trivial problem of deciding whether a density matrix of a composite quantum system exhibits entanglement. In my talk, I will focus on trying to formulate that problem precisely, as well as presenting generally known answers to it and my own results in this matter that I have been working on during my graduate studies.

Seminarium odwołane z powodu święta - Boże Ciało

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Seminarium odwołane z powodu spotkania wyborczego do Rady Wydziału

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mgr Mariusz Adamski

Critical Scaling of Quantum Fidelity

Quantum fidelity was first introduced in the field of quantum information processing. It has been postulated to be also useful in the study of the properties of quantum critical points. Scaling laws have been derived, which promise a simpler alternative to established, but cumbersome methods. In this talk I will show some results of practical application of fidelity approach to the case of a two dimensional exactly diagonalizable fermion model, with the aim to verify and compare the performance of this method to the traditional approach.

prof. dr hab. David Blaschke (IFT)

Generalized Beth--Uhlenbeck formulas from the $Phi-$derivable approach in 2-loop approximation

A dense fermion system with strong two-particle correlations (bound and scattering states = composite bosons) is considered within the Phi-derivable approach to the thermodynamic potential. It is shown that in the two-loop approximation for the Phi-functional of this fermion-composite boson system important cancellations hold which are one key element in the proof that the thermodynamic potential takes the form of a generalized Beth-Uhlenbeck formula. The other element are generalized optical theorems. It is shown that generalized Beth-Uhlenbeck formulas also hold for the other thermodynamic functions (entropy, density) which all assume the generic form of an energy-momentum integral over a statistical distribution function multiplied with a unique spectral density. In the near mass-shell limit, contrary to naive expectations, the latter reduces not to a Lorentzian but rather to a so-called "squared Lorentzian" shape. The developed formalism extends the validity of the Beth-Uhlenbeck approach beyond the low-density limit. It includes the Mott-dissociation of bound states in accordance with the Levinson theorem and the selfconsistent backreaction of the correlations to the propagation of the elementary fermions.

dr Pasi Huovinen

The hunt for (almost) perfect fluid

The fundamental building blocks of matter, quarks and gluons, are always confined to form hadrons. However, we expect that in extremely large temperatures and densities this confinement would be broken and quarks and gluons would move freely forming so called quark matter or quark-gluon plasma. It is believed that such a state of matter did exist a few milliseconds after the big bang, and that it has been recreated in ultrarelativistic heavy-ion collisions of large nuclei in the experiments at Brookhaven National Laboratory and CERN. It looks like that the matter created in these collisions has extraordinary properties like such a low kinematic viscosity that it has been described as perfect fluid. In this talk I will describe how we have come to believe that quark-gluon plasma has been created in the heavy-ion collisions, and our attempts to evaluate its hydrodynamical properties.

Seminarium odwołane z powodu wycofania się referenta

Dr. Vadim Dmitriev (Saratov State University)

Kinetic equation approach to massive vector boson production from vacuum within the inertial mechanism

The kinetic theory approach to describe the vacuum creation of vector bosons with dynamical mass is applied to a conformal cosmological model. We discuss this process as an additional source for the cosmic microwave background (CMB) radiation originating from the cosmological electroweak phase transition.

mgr Jarosław Gołembiewski

Power exponential velocity distributions in disordered porous media

Velocity distribution function (vdf) link the micro- and macro-level theories of fluid flow through porous media. Several reports, by different research groups, about vdf in porous media are already available. The findings, however, appear to be inconsistent with each other. On the one hand, theoretical [1], experimental [1] and numerical [2] results suggest that the vdf can be approximated by a Gaussian. On the other hand exponential [3, 4] or even stretched exponential [5] functions were also reported. To reconcile these contradictions, we propose that the velocity distribution functions follow the power exponential distribution. Using the Lattice Boltzmann Method we verify our hypothesis in a stochastically generated porous media. To this end we study distributions of the fluid absolute velocity and its longitudinal and lateral components relative to the macroscopic flow direction in various configurations, porosities and boundary conditions. We claim that all these velocity distributions follow the power exponential law controlled by an exponent and a shift parameter and find how these parameters depend on the porosity [6].

Dr. Manuel Krämer (IF USz)

Quantum cosmology and applications of the Wheeler-DeWitt equation

The unification of quantum theory and gravity is one of the most crucial open problems in physics. It is necessary to have a theory of quantum gravity in order to consistently describe Nature and to resolve singularities that are inherent in General Relativity. Several approaches to a theory of quantum gravity have been developed, but in order to ultimately decide which approach describes Nature best, we need testable predictions. A promising scenario to look for such effects is the highly energetic inflationary phase in the very early universe, which can be studied within the framework of quantum cosmology. Furthermore, quantum-cosmological models also serve as a mathematically simpler testbed to study conceptual questions of quantum gravity. In this talk, I will give an introduction to a rather conservative approach to quantum cosmology based on a canonical quantization that leads to the Wheeler-DeWitt equation. I will present how this approach has been applied to study whether quantum-gravitational corrections to the power spectra of inflationary perturbations can be observed in the Cosmic Microwave Background and whether singularities that appear in classical cosmology can be resolved.

dr Pok Man Lo (IFT)

Repulsive interactions and their effects on the thermodynamics III

Continuation:  In  this talk  we  compare  two approaches  in  modeling repulsive interactions among  hadrons: the excluded­volume approximation and the S ­matrix formalism. The latter  provides  a consistent  treatment  of broad  resonances  based  on empirical  scattering  phase shifts.  We  shall  apply these  techniques  to  study the thermodynamics  of  the (πN∆)  system,  with  a particular  focus  on  the fluctuation  of baryon charge in the thermal medium. Limitations of the methods in describing dense hadronic matter would be briefly discussed.

dr Michał Eckstein (Instytut Fizyki UJ)

The noncommutative geometry of fundamental interactions

Noncommutative geometry a la Connes offers a new perspective on models of particle physics. It provides a geometrical dressing for the Standard Model along with new, concrete predictions. I will present the rudiments of Connes theory and provide an outlook into the possible applications. I will complement the general theory with a brief discussion of my own results concerning the causal structure.

Dr. Yuriy Karpenko (INFN and University of Florence),

Viscous hydro + cascade modeling of heavy ion collisions at \sqrt{s_{NN}} = 7.7-200 GeV

State-of-the-art 3D viscous hybrid model is applied to heavy ion collisions at RHIC Beam Energy Scan (BES) energy range \sqrt{s}=7.7...200 GeV. The model employs the hadron transport approach UrQMD for the early and late non-equilibrium stages of the reaction, and 3+1 dimensional viscous hydrodynamics for the hot and dense quark-gluon plasma stage. It includes the equation of motion for finite baryon number, and employs an equation of state with finite net-baryon density to allow for calculations in a large range of beam energies. The parameter space of the model is explored, and constrained by comparison with the experimental data for bulk observables from SPS and the phase I BES at RHIC. The favored parameter values depend on energy, but allow to extract the effective value of the shear viscosity coefficient over entropy density ratio \eta/s in the fluid phase for the whole energy region under investigation. The estimated value of effective \eta/s increases with decreasing collision energy, which may indicate that \eta/s of the quark-gluon plasma increases with increasing baryochemical potential \mu_B.

Krzysztof Cebrat

Analiza stanu miast za pomocą sieci neuronowych.

Referat omawia zastosowanie sieci neuronowej Kohonena do analizy wielowymiarowych danych dotyczących miast. Badania pozwoliły pogrupować miasta według podobieństwa wybranych cech opisujących energetyczną część metabolizmu miast, oraz określić zależności, na przykład pomiędzy wielkością czy położeniem geograficznym miasta a cechami grupy, do której zostało przyporządkowane. W połączeniu z zastosowaniem algorytmów genetycznych opisano wagi poszczególnych cech i udział podsystemów strukturalnych miasta w grupowaniu miast. Wskazano na znaczącą rolę sposobu, w jaki miasto przetwarza dostępne zasoby energetyczne oraz odkryto nieliniową zależność niektórych istotnych cech od położenia w sieci. Opierając się na analogiach między miastami a ekosystemami, cechy opisujące bilans energetyczny miast i wielkości przepływów energetycznych w jego granicach, powinny również wskazywać potencjał rozwojowy miast.

prof. dr hab. Ziemowit Popowicz

Weak solutions - peakon equations

The Fermi-Pasta-Ulam (FPU) problem gave birth to the investigation of soliton theory. The complete integrability of soliton systems explains also the FPU problem. I present in my talk the completely integrable systems with the weak solutions. I discuss the so called peakon equations: Comassa-Holm, Degasperis-Procesi, Novikov, and their different generalizations.

dr. hab Janusz Szwabiński

Relacje między konformizmem i antykonformizmem a polaryzacja grup społecznych.

Burzliwe debaty prowadzące do polaryzacji grup społecznych obserwowane są w wielu dziedzinach. Panuje obecnie przekonanie, że istnieje silna korelacja między polaryzacją a segmentacją społeczności, jednak ciągle wiemy niewiele na temat mechanizmów prowadzących do wykształcania się skrajnych opinii między segmentami. W trakcie wykładu przedstawię wyniki badań, w ramach których użyliśmy modelowania agentowego do sprawdzenia, czy wypadkowa konformizmu i antykonformizmu może być przyczyną polaryzacji społeczności podzielonej na grupy. Punktem wyjścia był model q-votera, do którego dodaliśmy antykonformizm jako drugi typ oddziaływań oraz sieć o strukturze podwójnej kliki celem uwzględnienia podziałów w obrębie społeczności. Nasze wyniki rzeczywiście wskazują, że wzajemna relacja między konformizmem wewnątrz klik a antykonformizmem pomiędzy nimi może prowadzić do polaryzacji, o ile liczba antagonistycznych połączeń między klikami jest na odpowiednio wysokim poziomie.

dr Pok Man Lo (IFT)

Repulsive interactions and their effects on the thermodynamics II

Continuation: In this talk we compare two approaches in modeling repulsive interactions among hadrons: the excluded-volume approximation and the S-matrix formalism. The latter provides a consistent treatment of broad resonances based on empirical scattering phase shifts. We shall apply these techniques to study the thermodynamics of the (πN∆) system, with a particular focus on the fluctuation of baryon charge in the thermal medium. Limitations of the methods in describing dense hadronic matter would be briefly discussed.

Wielki Piątek - nie ma seminarium

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dr Arkadiusz Błaut

First direct detection of a gravitational wave

On 14 September 2015 gravitational waves have been detected for the first time by the two LIGO detectors in Hanford, Washington, and Livingston, Louisiana US. The strong signal was generated by the collision of two black holes 1.3 billion years ago. I will present the discovery giving first an introduction to the gravitational waves physics and methods of their detection.

mgr Łukasz Tracewski

Towards global biodiversity monitoring

In the context of expanding and intensifying human land-use, pressures on natural populations of plants and animals are ever-increasing. In particular, habitat loss and fragmentation strongly affects the viability of natural biodiversity. The United Nations Assembly declared this decade, 2011 – 2020, the Decade on Biodiversity and set a strategic plan for conservation of biodiversity: the Aichi targets. The critical aspect of meeting these goals is a global monitoring system. The potential of using remote sensing, and satellite imagery in particular, is widely recognised, although largely unfulfilled at a global scale. One of its critical missing pieces are efficient ways of measuring habitat fragmentation that take into account species home range, which is exactly what I would like to address in my research.

dr Pok Man Lo (IFT)

Repulsive interactions and their effects on the thermodynamics

In this talk we compare two approaches in modeling repulsive interactions among hadrons: the excluded-volume approximation and the S-matrix formalism. The latter provides a consistent treatment of broad resonances based on empirical scattering phase shifts. We shall apply these techniques to study the thermodynamics of the (πN∆) system, with a particular focus on the fluctuation of baryon charge in the thermal medium. Limitations of the methods in describing dense hadronic matter would be briefly discussed.

dr hab. Lech Jakóbczyk

Geometryczny dyskord dwóch qutritów

Omówię rezultaty ostatni opublikowanej pracy: L. Jakóbczyk, A. Frydryszak, P. Ługiewicz,"Qutrit geometric discord".

dr Thomas Klähn

Quarks in Compact Stars - Truth or Fiction?

The equation of state (EoS) is one of the keys to understand observational data from supernovae and compact stars. The intrinsic connection between the macroscopic structure and evolution of these objects and the underlying fundamental interactions between the constituent particles on the microscopic level challenges our understanding of nature on both scales. During the presentation a brief overview of constraints on the EoS from terrestrial experiments, astrophysical observations, and theoretical considerations is given. The extreme densities that can be reached in the core of compact stars give reason to the assumption that in this domain hadrons might dissolve and a deconfined quark gluon plasma forms. The second part of the presentation discusses resulting questions: How do we describe deconfined quarks and deconfinement? Do our quark matter models agree with observational data? Can we decide whether quark matter in compact stars is a reality?

prof. dr hab. David Blaschke (IFT) at 10:00!

The universal symmetry energy conjecture

The difference between the energy per nucleon in pure neutron matter and in symmetric nuclear matter (SNM) is called the (a)symmetry energy. It plays a key role when relating the equation of state in SNM as probed, e.g., in heavy-ion collisions, with the one that govern the structure and composition of neutron stars. We prove that the symmetry energy contribution to the neutron star equation of state (beta- equilibrium and charge neutrality) is a universal function of the density for densities above saturation, provided that the direct Urca cooling process is inhibited. Phenomenology of compact star cooling supports the fulfilment of this constraint.

dr Tomasz Tylec (Warszawa)

Teorie niesygnalizujące w formalizmie logik kwantowych

Tzw. teorie niesygnalizujące w ostatnim czasie zdobyły niemałą popularność w niektórych działach teorii informacji kwantowej. Wprowadzane są one jednak zazwyczaj w sposób, który wydaje się bardzo intuicyjny, jednakże z matematycznego punktu widzenia wątpliwy. W referacie zaprezentowane zostanie ich umocowanie w formalizmie logik kwantowych i pewne konsekwencje dla ich właśności z tego płynące. Jedną z konsekwencji jest to, iż wbrew powszechnemu mniemaniu, traktowanie teorii niesygnalizujących jako uogólnień mechaniki kwantowej (czy raczej teorii prawdopodobieństwa kwantowego) jest nieuzasadnione.

Prof. Yudai Suwa (Kyoto University and Max-Planck Institute for Astrophysics, Garching)

From supernovae to neutron stars

A core-collapse supernova is the generation site of a neutron star as well as one of the largest explosions in the Universe. In this talk, I will show our recent results from multi-dimensional neutrino-radiation hydrodynamics simulations, especially focusing on neutron star formation.

Juan M. Torres-Rincon (Subatech, IN2P3/CNRS, Universite de Nantes)

Revisiting the equation of state of hot matter using the Polyakov-Nambu-Jona-Lasinio model

The phase diagram is one of the key features of hot and dense matter. First-principles QCD calculations, like QCD on a lattice, only provide reliable knowledge in very limited regions of this diagram. A more global (but approximate) description of the thermal properties of QCD can be achieved through effective models, like the Polyakov-Nambu-Jona-Lasinio model. This model is able to map the whole phase diagram at finite temperatures and densities, but the standard equation of state at mean-field level, already at zero baryonic density, presents strong tensions with the results provided by lattice-QCD calculations. I revisit the foundations of the model and the calculation of the thermodynamic potential to improve the description of the equation of state and make it compatible with current lattice-QCD results.

Dr. Stijn van Tongeren (Uniwersytet Humboldta, Berlin)

Kappa-Poincare symmetry in string theory and AdS/CFT

The kappa-Poincare algebra is a deformation of the Poincare algebra that has been intensively studied over the last decades as a possible structure arising out of quantum gravitational effects. I will discuss how this type of symmetry algebra appears in a different context, namely string theory and the AdS/CFT correspondence. Here kappa-Poincare type algebras turn out to describe the symmetries of strings that are related to strings moving in anti-de Sitter backgrounds by a double Wick rotation. These strings play an important role in advanced tests of the AdS/CFT correspondence. My talk will consist of two parts. I will begin my talk with an introduction to the AdS/CFT correspondence and strings in anti-de Sitter backgrounds. The strings we will consider turn out to be integrable, a feature which allows us to compute their exact spectra. This requires us to consider their double Wick rotated versions, however, which turn out to be strings in different backgrounds. Having established these models, I will discuss how to deform them to realize quantum algebra type symmetries. In a special limit these quantum algebras become kappa-Poincare type algebras, while the models themselves become the models describing our double Wick rotated strings.

prof. dr hab. Zbigniew Haba

Kosmologia i termodynamika ****** Cosmology and thermodynamics

Omówię zastosowanie termodynamiki i fizyki statystycznej do opisu ewolucji Wszechświata i wynikające stąd wnioski. Przedstawię model opisujący ewolucję Wszechświata za pomocą funkcji rozkładu prawdopodobieństwa w przestrzeni fazowej ciemnej materii. ****** Application of thermodynamics and statistical physics to a description of the Universe evolution and resulting conclusions thereof will be described. A model representing this evolution by means of the dark matter phase space distribution will be discussed.

dr hab. Janusz Szwabiński

Kilka luźnych przemyśleń na temat modelu epidemiologicznego SIR

prof. dr hab. Jerzy Lukierski

Quantum Deformations of Space-Time and Deformations of String Backgrounds

The aim of my talk is threefold: 1) To recall the appearance of noncommutative space-time ("quantum space-time") in context of quantization of gravity. 2) To show the use of classical r-matrices defined for space-time symmetry algebras for the classification of possible quantum space-times. 3) To employ the classical r-matrices to the description of deformations of dynamical models, in particular: -- a) in field theory - to the introduction of star-product multiplication of deformed fields, -- b) in string theory - to the deformation of string actions represented as two-dimensional sigma models (deformed string actions <- -> Yang-Baxter sigma models). The aims 2) and 3) were investigated in three publications which appeared in October and November 2015 (arXiv:1510.09125, arXiv:1510.03083, arXiv:1511.03653).

dr Thomas Klaehn (ITF)

QCD gap equations and fractal structures? A simple model study

QCD's gap equations are self-consistent by their very nature. A typical method to solve them is to iterate an initial guess to a stable solution. As it is well known that more than one solution exists the question arises how and whether we obtain the correct one. We present a simple model where all solutions can be obtained from solving a polynomial equation and compare with results from the iterative method. We show that the method provides an in principle infinite amount of further solutions. To understand this behaviour as a consequence of the iterative approach we discuss fractal properties of the gap equation.

Jakub Żmuda

Produkcja pionów w generatorach Monte Carlo

Omówione zostanie zagadnienie modelowania produkcji pionów w generatorach Monte Carlo oddziaływań neutrin. Przedyskutowane bedą najważniejsze niepewności w opisie tego procesu oraz różnice pomiędzy poszczególnymi generatorami i zawartymi w nich modelami fizycznymi.

Seminarium odwołane z powodu wycofania się referenta.

The seminar is canceled due to the speaker's withdrawal.

Mateusz Bancewicz i Jakub Poła

4-way resolved particle fluid flow simulations using CFD-DEM approach.

Modelowanie przepływów za pomocą algorytmów CFD-DEM umożliwiaja symulację układów złożonych z płynów i cząstek stałych, uwzględniając przy tym oddziaływania zarówno płyn - cząstka jak i oddziaływania pomiędzy samymi cząstkami. Metoda ta umożliwia analizę układów dla których liczba Knudsena jest znacząco większa od 1. W prezentacji przedstawimy podstawy teoretyczne tej metody, która jako solver CFD używa metody gazu sieciowego Boltzmanna jak i metody objętości skończonych. Przedstawimy jej potencjalne zastosowanie w symulacjach transportu propantów w szczelinach powstających w procesach stymulacji złóż gazów łupkowych.

Krzysztof Graczyk

Sieci neuronowe w modelowaniu czynników postaci nukleonu

Przedstawiona zostanie metoda bazująca na metodach Bayesowskich sieci neuronowych pozwalająca na uzyskanie bezmodelowej informacji z analizy danych nie tylko pomiarowych. Omówię zastosowanie tego formalizmu do uzyskania informacji o elektromagnetycznych czynnikach postaci, promienia protonu oraz poprawek dwu-fotonowych.

Tomasz Bednarz

Four hats: engineering, art, science and design

This presentation will showcase various projects that I was part of, at the Kyushu University, James Cook University, CSIRO and now at the QUT. There won't be a particular focus, as I rather prefer to show wide range of capabilities and use cases, that could be later further discussed, and possibly initiate collaborations. I will pick up few examples, that could be of interest to scientific community. So, please join, if you want to hear about flying frogs, how to make zero-gravity in terrestrial environments, see how diurnal temperature influences exchange flows in reservoirs, how to measure temperature non-invasively, how to build interactive tele-operating systems, how to prepare and build human-computer interaction experiments, generate 360 degrees panorama. Also, how to use PDEs and GPUs to detect cancer from micro CT-scans, how to build Virtual Laboratory that runs in clouds and executes wide range of image analysis and image processing operations, how to look at modern big data analytics, visual analytics and visualisation frameworks, and at the end how to connect design, art, science and engineering together.

mgr Aneta Wojnar

Inflationary cosmology with Chaplygin gas in Palatini formalism

We present a simple generalisation of the LCDM model which on the one hand reaches very good agreement with the present day experimental data and provides an internal inflationary mechanism on the other hand. It is based on Palatini modified gravity with quadratic Starobinsky term and generalized Chaplygin gas as a matter source providing, besides a current accelerated expansion, the epoch of endogenous inflation driven by type III freeze singularity. The dynamics is reduced to the 2D sewn dynamical system of a Newtonian type. For this aim we use dynamical system theory. We classify all evolutional paths in the model as well as trajectories in the phase space. We demonstrate that the presence of a degenerate freeze singularity (glued freeze type singularities) is a generic feature of early evolution of the Universe.

prof. dr hab. D. Blaschke (IFT)

Three-fluid hydro based event simulation for collisions at NICA and FAIR energies

I describe a new event generator that is based on a three-fluid hydrodynamics description of the early stage of the collision, followed by a particlization at the chemical freeze-out to join a UrQMD "afterburner" accounting for hadronic final state interactions and a GEANT simulation of the detector response. I present first results for the FAIR/NICA energy scan ($sqrt{s_{NN}}=4-11$ GeV) addressing the directed flow of protons and pions as well as the proton rapidity distribution for two model EoS, with and without a first order phase transition. The new program has the unique feature that it can describe a hadron-to-quark matter transition of first order which proceeds in the baryon stopping regime that is not accessible to previous simulation programs designed for higher energies and assuming transparency of the colliding nuclei.

Wim Cosyn (Ghent University)

The quest for short-⁠range correlations with electron scattering on nuclei

We give an overview of recent progress made in the description of short-range correlations (SRC) in nuclei. On the experimental side, inclusive A(e,e') and exclusive A(e,e'pN) scattering experiments over the whole nuclear mass range have yielded interesting results about the mass dependence and isospin composition of the nuclear SRC. Especially for the exclusive two-nucleon knockout measurements, theoretical models estimating the effect of final-state interactions (FSI) are indispensable to extract meaningful results from the data. We introduce a model that accounts for these FSI and also discuss a method to count the number of SRC pairs in any nucleus. Comparisons with the existing measurements are made and discussed.

prof. Ludwig Schultz, Institute of Metallic Materials, IFW Dresden

Superconducting Levitation - physics and applications

mgr Łukasz Tracewski

Obliczenia rozproszone z wykorzystaniem Apache Spark

Apache Spark jest narzędziem umożliwiającym rozproszone przetwarzanie danych. Łatwość konfiguracji i programowania nań, połączona z wysoką skalowalnością i wydajnością, sprawiła, że w ostatnim czasie zyskał on ogromną popularność zarówno w przemyśle, jak i w środowisku akademickim. Oprócz algorytmów ogólnego przeznaczenie dostarcza on również szeroki wachlarz algorytmów samouczących i możliwość obliczeń na grafach. Do dyspozycji użytkownika są interfejsy w języku Python, Java, Scala i R. Apache Spark jest dostępny na PL Grid. W trakcie seminarium przedstawię pokrótce technologię stojącą za Apache Spark, a następnie przejdę do praktycznej demonstracji możliwości narzędzia na niewielkim klastrze obliczeniowym.

prof. dr hab. Ludwik Turko (IFT)

Particle in strong fields

Problems related to the description of particles bound by strong external fields are present on all levels of the theory - started from the classical, then quantum mechanical, then quantum field theoretical formulations. A number of new effects is then expected as spontaneous positron emission or an appearance of condensates. Short review of problems on different levels will be given.

Natalie Jachowicz (Ghent U.)

Modeling QE neutrino-nucleus scattering in MiniBooNe and T2K

(Seminar via Skype) Neutrino-oscillation experiments rely on neutrino-nucleus scattering to detect the neutrinos carrying the oscillation signal. A precise understanding of the mechanisms underlying the interaction of the neutrino with an atomic nucleus is mandatory to disentangle the oscillation pattern. This quest for the precise determination of oscillation parameters is complicated by the fact that monochromatic neutrino beams are not available, and neutrinos are produced with a broad energy distribution. The signal in a detector is hence the superposition of different reaction mechanisms : quasi-elastic, multi-nucleon emission, pion-production etc., which all need to be understood. Here, we focus on single-nucleon knockout processes and present continuum random phase approximation (CRPA) results for charged-current quasielastic (CCQE) neutrino-nucleus scattering at kinematics relevant for the MiniBooNe and T2K experiments. We pay special emphasis to low-energy nuclear excitations that are well described by the CRPA formalism and provide a non-negligible contribution to reaction cross sections for low incoming energies or forward scattering.

prof. Marek Abramowicz (Physics Department of Goeteborg University)

Astrophysical black holes, large and small

I will review the observational evidence for the existence of "stellar mass" and "supermassive" black holes.

dr Viktor Begun (UJ Kraków)

Pion condensation as a solution of the LHC proton-pion puzzle

In this talk I will review the recent success of the non-equilibrium hadronization model in describing the LHC data from PbPb collisions at 2.76 TeV. This approach allows to describe the measured particle multiplicities and spectra in a very economic way. It further predicts Bose-Einstein condensation for pions. This intriguing possibility will be addressed in details for finite systems with the use of higher order moments of the multiplicity distribution.

Joanna Zalipska (NZBJ)

Pomiar oddziaływań 2p2h w eksperymencie T2K

Seminarium poświęcone będzie oddziaływaniom neutrin na wielu nukleonach (oddziaływania 2p2h), które dopiero od niedawna jest uwzględniane w modelowaniu oddziaływań neutrin. Omówiony zostanie wpływ oddziaływań tego typu na główne analizy prowadzone w eksperymencie akceleratorowym T2K w Japonii. Pokazane zostaną pierwsze próby zmierzenia przekroju czynnego oddziaływań 2p2h na podstawie ostatnich analiz danych bliskiego detektora eksperymentu T2K. Ponadto dyskutowane będą analizy dedykowane poszukiwaniom sygnatury oddziaływań 2p2h.

dr Chihiro Sasaki, prof. UWr (IFT)

The phase structure of Quantum Chromodynamics

The studies of the QCD phases and thermodynamics at finite temperature and baryon density is of crucial importance in heavy-ion phenomenology. We will give a brief overview on QCD thermodynamics including recent developments from lattice QCD and effective theory approach. The following selected issues will be discussed; interplay between confinement and dynamical chiral symmetry breaking, hadrons near chiral symmetry restoration, correlations between light and heavy flavors.

prof. dr hab. Ludwik Turko (IFT)

Cancelled: Particle in strong fields

Cancelled: Problems related to the description of particles bound by strong external fields are present on all levels of the theory - started from the classical, then quantum mechanical, then quantum field theoretical formulations. A number of new effects is then expected as spontaneous positron emission or an appearance of condensates. Short review of problems on different levels will be given. Cancelled

dr hab. Marek Mozrzymas

Application of majorisation in Quantum Information Theory

A recent results in Quantum Information Theory have shown that majorisation is a powerful and efficient tool in this theory. The usefulness of majorisation in Quantum Information Theory is a consequence of the relation between the majorisation relation and the unitarity, which plays a fundamental role in Quantum Mechanics. In this review lecture I would like to introduce the concept of majorisation and to present some examples of application of majorisation in Quantum Information Theory. In particular I would like to show what are the connections between entatnglement and majorisation and some applications of majorisation in the domain of local transformations of bipartite states.

Maciej Matyka

Implementacja Multiple Particle Collision i dostosowanie do przepływu Darcy'ego

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Święto Uniwersytetu - seminarium odwołane

Dr hab. Tomasz Zaleski, INTiBS Wrocław

Polish "Nobel Prize" 2015: ultracold atoms. Spectroscopy of ultracold bosons in optical lattices.

Ultracold, trapped atoms are model systems allowing for direct observation of quantum many-body effects. They are of high importance not only for understanding of physics of solids, but also quantum optics, while finding many applications, e.g. in metrology. Owing to precise measurements and direct relation between theoretical description and experimental settings, they are also a perfect tool for validating models and approximations used to describe them. During my talk I will present a method of determining interatomic correlations and calculating dynamic structure factor of ultracold bosons, which can be measured using Bragg spectroscopy. This method uses a pair of laser beams to directly transfer energy and momentum to ultracold atoms allowing for studies of excitation spectra, similarly to angle-resolved photoemission spectroscopy (ARPES) widely used in investigations of solid-state systems.

1. Łukasz Juchnowski, 2. dr hab. Dariusz Prorok - IFT

1. Nonequilibrium meson production in strong fields 2. Does the low p_T pion enhancement occur in Pb-Pb collisions at the LHC, really?

Ł.J.:I will briefly introduce a kinetic equation approach to nonequilibrium pion and sigma meson production in a time-dependent, chiral symmetry breaking field (inertial mechanism). Our investigation focuses on the low-momentum pion enhancement observed in heavy-ion collisions at CERN - LHC. In this preliminary study, we consider the inertial mechanism for nonequilibrium production of the sigma mesons and their simultaneous decay into pion pairs for two cases of sigma mass evolution. The resulting pion distribution shows a strong low-momentum enhancement. D.P.: Many data in the High Energy Physics are, in fact, sample means. It is shown that when this exact meaning of the data is taken into account and the most weakly bound states are removed from the hadron resonance gas, the acceptable fit to the whole spectra of pions, kaons and protons measured at midrapidity in central Pb-Pb collisions at $sqrt{s_{NN}} = 2.76$ TeV is obtained. Low $p_{T}$ pions and protons are reproduced simultaneously as well as $p/pi$ ratio. Additionally, correct predictions extend over lower parts of large $p_{T}$ data.

Xianguo Lu

Transverse kinematic imbalance in neutrino interactions

In recent studies, several novel variables of transverse kinematic imbalance in neutrino interactions have been proposed and their significance to neutrino energy spectrum reconstruction and nuclear effects was discussed in Refs. [1, 2]. In this seminar, we would like to present the details of our studies with the predictions by the NuWro generator. [1] X.-G. Lu et al. "Reconstruction of Energy Spectra of Neutrino Beams Independent of Nuclear Effects," Phys.Rev. D92 (2015) 5, 051302. [2] X.-G. Lu, L. Pickering, S. Dolan, G. Barr, D. Coplowe, Y. Uchida, D. Wark, M. Wascko, A. Weber, and T. Yuan, "A study of nuclear effects in neutrino interactions using transverse kinematic imbalance,'' in preparation.

prof. dr hab. Jan Sobczyk

Nobel Prize in Physics 2015

I will review neutrino oscillation studies that were awarded by the 2015 Physics Nobel Prize.

Aleksandr Dubinin (IFT)

Mott-hadron resonance gas and lattice QCD thermodynamics

We (D.Blaschke, A.D., L.Turko) present an effective model for the generic behavior of hadron masses and phase shifts at finite temperature which shares basic features with recent lattice QCD results within the PNJL model for correlations in quark matter. On this basis we obtain the transition between a hadron resonance gas phase and the quark gluon plasma in the spirit of the generalized Beth-Uhlenbeck approach where the Mott dissociation of hadrons is encoded in the hadronic phase shifts. We find that the restriction to low-lying hadronic channels is justified by the rather low chiral transition temperature found in recent lattice QCD thermodynamics results.

prof. dr hab. Piotr Kosiński (Uniwersytet Łódzki)

"Egzotyczna" symetria Poincare ****** "Exotic" Poincare symmetry

Reguły transformacji stanów cząstek ze spinem wykazują pewne osobliwości, jeżeli do zbioru zmiennych dynamicznych dołączymy, oprócz pędu i spinu, również współrzędne przestrzenne. Okazuje się jednak, że możliwy jest spójny i zgodny z "ortodoksją" opis tych, w pewnym sensie pozornych, osobliwości. ******* Transformation properties of particles with spin exhibit some peculiarities if one includes coordinate variables. However, it appears that the consistent description of these "exotic" transformations is possible.

Michał Marczenko - IFT

Matching Hagedorn mass spectrum with Lattice QCD

Recent Lattice QCD studies suggest that there are missing resonances in the strange sector of the hadron resonance gas model. We show how an improved fit for the Hagedorn mass spectrum, consistent with lattice QCD data for both equation of state and fluctuations of conserved charges, can account for these missing resonances.

dr Janusz Miśkiewicz

Analiza korelacji krzyżowych układów złożonych ******* Cross-correlation analysis of complex systems

Wynikiem pomiaru ewolucji układu jest szereg czasowy. W przypadku układu złożonego jego ewolucja jest opisywana przez nie jeden a wiele szeregów czasowych. Co ważniejsze, wzajemne oddziaływanie elementów składowych znajduje swe odzwierciedlenie w korelacjach krzyżowych szeregów czasowych. W referacie przedstawiony zostanie problem analizy korelacji krzyżowych układów złożonych w ekonofizyce. Istotnym elementem, który wpływa na stosowane tu metody, jest rozmiar układu. W rezultacie analiza korelacji krzyżowych składa się z dwóch etapów: analizy korelacji pomiędzy szeregami i badania otrzymanej macierzy korelacji. W referacie zostaną  przedstawione zarówno metody standardowe jak i opracowane przeze mnie w toku prowadzonych badań. ******* The evolution of a system is recorded in as a time series. In the case of a complex system  its evolution is described by more than one time series. More importantly, the interactions of the subsystems are reflected by the cross-correlations of time series. In the seminar the problem of cross-correlation analysis in econophysics  will be presented. The important element which affect the analysis here is the size of the system. As a result, the cross-correlation analysis is divided into two stages: analysis of the correlation among the series and the study of the correlation matrix. The standard approach will be compared with chosen alternative methods.

prof. dr hab. Detlef Hommel (IFD)

Solid State Lighting - energy saving on a global scale: for environment and consumers

The invention of blue InGaN/GaN light emitting diodes (LEDs) by Shuji Nakamura in 1993 was a breakthrough for the development of white LEDs for global lighting. In a first part the historical situation at the beginning of the 90's will be reviewed followed by a more detailed desciption of achievements by the three last year Nobel Prize winners in Physics. Whereas Profs. I. Akasaki and H. Amano developed the physics of the Group-III nitrides Prof. S. Nakamura found not only the practical solutions for p-doping but also invented InGaN quantum wells as active Region. In a second part the principles of white light emission will be discussed as well as energy saving potencial of SSL (solid state lighting). Finally an outlook of future developments and challanges will be given.

Pan Dziekan zaprasza

Uroczysta immatrykulacja studentów Wydziału Fizyki i Astronomii

O 12.00 spotykamy się w Auli Leopoldinum na uroczystej immatrykulacji naszych studentów. Uroczystość potrwa do godz. 13. W tym czasie są też ogłoszone godziny dziekańskie.

Prof. Pawel Danielewicz (Michigan State University, East Lansing, USA)

Symmetry Energy: from Nuclei to Neutron Stars

Symmetry energy quantifies the changes in nuclear energy when isospin grows away from zero, at finite baryon number. Knowledge of the symmetry energy is critical when extrapolating from nuclei to neutron stars. Charge invariance of nuclear interactions implies that the dependence of energy on isospin is primarily quadratic.  Relying on the charge invariance, we examine nuclear excitation energies to the isobaric analog states of ground states of other nuclei in the same isobaric chain. In this fashion we are able to extract symmetry-energy coefficients on a nucleus-by-nucleus basis. The coefficients turn out to have a strong mass dependence that can be tied to different contributions from different densities in nuclei with different mass.  In consequence, we are able to deduce constraints on the symmetry energy in nuclear matter, as a function of density. Those constraints are narrow at subnormal densities, but spread out at normal density and above. Plans to constraint the symmetry energy at supranormal densities, using charged pion yields are discussed.

Dr. Pasi Huovinen (Universitaet Frankfurt)

Dynamical freeze-out in event-by-event hydrodynamics

In hydrodynamical modeling of the ultrarelativistic heavy-ion collisions the freeze-out is typically performed at a constant temperature. The more physical choice is to use a criterion that freeze-out happens when the hydrodynamical expansion rate exceeds the scattering rate of particles. I'll show how this uncertainty in freeze-out criterion affects the anisotropies v_2 and v_3 in event-by-event calculations.

mgr Łukasz Tracewski

Obliczenia rozproszone z wykorzystaniem Apache Spark

Apache Spark jest narzędziem umożliwiającym rozproszone przetwarzanie danych. Łatwość konfiguracji i programowania nań, połączona z wysoką skalowalnością i wydajnością, sprawiła, że w ostatnim czasie zyskał on ogromną popularność zarówno w przemyśle, jak i w środowisku akademickim. Oprócz algorytmów ogólnego przeznaczenie dostarcza on również szeroki wachlarz algorytmów samouczących i możliwość obliczeń na grafach. Do dyspozycji użytkownika są interfejsy w języku Python, Java, Scala i R. Apache Spark jest dostępny na PL Grid. W trakcie seminarium przedstawię pokrótce technologię stojącą za Apache Spark, a następnie przejdę do praktycznej demonstracji możliwości narzędzia na niewielkim klastrze obliczeniowym.

seminarium 5 czerwca odwołane

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Na wniosek referenta seminarium IFT dnia 5.06.2015 zostało odwołane. Planowany referat odbędzie się w innym terminie.

mgr Tomasz Trześniewski

The deformed Carroll particle from 3d gravity

Classical gravity in 2+1 dimensions can be formulated as the Chern-Simons theory with a local isometry group as the gauge group. Point particles may be coupled to this theory in a natural way. In principle one can then integrate out the gravitational degrees of freedom and obtain the effective particle action but in the case of de Sitter space it is rather difficult. On the other hand, de Sitter gauge group locally factorizes into the Lorentz group and the group AN(2). For vanishing cosmological constant, corresponding to the flattening of the AN(2) component one recovers a particle in flat spacetime and with the momentum space given by the Lorentz group. It turns out that if one instead flattens the Lorentz component it leads to the ultrarelativistic particle solution, known as the Carroll particle but with the AN(2) momentum space. Interestingly, the AN(2) group is related to the three-dimensional kappa-Poincare algebra, a well-studied example of deformations of relativistic symmetries which hypothetically arise in the quantization of gravity.

Katarzyna Suska

Ettore Majorana and his last published paper "A symmetric theory of electrons and positrons"

In 1928, Paul Dirac discovered the theoretical framework for describing spin 1/2 particles, it seemed that complex numbers were unavoidable Dirac’s original equation contained both real and imaginary numbers, and therefore it can only pertain to complex fields. Ettore Majorana In his 1937 paper posed, and answered, the question of whether equations for spin 1/2 fields must necessarily, like Dirac’s original equation, involve complex numbers. Majorana discovered that, to the contrary, there is a simple, clever modification of Dirac’s equation that involves only real numbers. With this discovery, Majorana made the idea that spin 1/2 particles could be their own antiparticles theoretically respectable, that is, consistent with the general principles of relativity and quantum theory. In our semminar we will talk about Ettore Majorana`s last 9-th published paper "A symmetric theory of electrons and positrons".

Joanna Sobczyk

Modele rozpraszania elektron-jądro

Podczas seminarium przedstawię kilka modeli używanych do opisu oddziaływania elektronu z jądrem atomowym w przybliżeniu IA (impulse approximation). Zaprezentowane zostaną różne formalizmy i używane przybliżenia oraz ich wpływ na przekrój czynny.

dr Robert Falewicz (Instytut Astronomiczny UWr)

Numeryczne modelowanie mechanizmów transportu i deponowania energii w rozbłyskach słonecznych

Mechanizmy transportu i deponowania energii w rozbłyskach słonecznych są zbadane jedynie fragmentarycznie, choć ich zrozumienie jest niezwykle istotne dla rozwiązania takich zagadnień jak: bilans energii rozbłysków słonecznych, prognozowanie ich klasy i widma emisji, prognozowanie pogody kosmicznej, a nawet wpływu aktywności słonecznej na zjawiska geofizyczne. Z uwagi na złożoność i wzajemne powiązanie procesów fizycznych zachodzących w rozbłyskach słonecznych, bardzo trudno opisać je w sposób analityczny. Wykorzystanie modelowania numerycznego w oparciu o parametry obserwacyjne rozbłysków umożliwia zbadanie procesów zachodzących podczas rozbłysków, zrozumienie ich własności a także, sprawdzenie poprawności zastosowanych modeli i otrzymanych rozwiązań. Podczas referatu przedstawię różne podejścia i strategie, jakie można zastosować do modelowania, zaprezentuję także wyniki prób odtworzenia parametrów fizycznych realnych rozbłysków słonecznych oraz wnioski jakie można otrzymać na ich podstawie.

Introduction to Heavy ​Ion Collisions and Matter under Extreme Conditions X

Quark Matter for pedestrians

This is the tenth seminar/lecture talk performed within the monographic lecture course run by D. Blaschke, K. Redlich, L.Turko & Co. The course is devoted to master students, PhD students and all interested in the subject. More details in: http://panoramix.ift.uni.wroc.pl/pluginfile.php/10955/mod_resource/content/2/Monografic_Lecture_HIC 2015.pdf

Michał Marczenko

Matching Hagedorn mass spectrum to Lattice QCD

Recent lattice studies suggest that there are missing resonances in the strange sector of the hadron resonance gas (HRG) model. During my talk I will show how an improved fit for the Hagedorn mass spectrum, consistent with lattice data for both thermodynamics and fluctuations, can account for these missing resonances.

Dr Pok Man Lo, University of Wroclaw

Introduction to Heavy ​Ion Collisions and Matter under Extreme Conditions IX

Lattice QCD for pedestrians: This is the eighth seminar/lecture talk performed within the monographic lecture course run by D.  Blaschke,  K.  Redlich,  L.Turko & Co.  The  course  is  devoted  to  master  students,  PhD students and all interested in the subject. More details in: http://panoramix.ift.uni.wroc.pl/pluginfile.php/10955/mod_resource/content/2/Monografic_Lecture_HIC 2015.pdf

Prof. Ludwik Turko, IFT, University of Wroclaw

Statistical physics of excluded volume effects for hadrons

The effects of attractive and repulsive interactions among hadrons lead to excluded volumes occupied by the hadrons – as in the Van der Waals equation. The need for the consistent description of fluctuations and phase transition phenomena makes necessary to introduce chemical potentials and use statistical physics machinery. A recent progress in this field will be reported.

dr Pok Man Lo (IFT)

Phase Diagram of QCD

A brief and biased overview of the QCD phase diagram is presented from two perspectives: (1) confinement, and (2) spontaneous chiral symmetry breaking. The first part chiefly consists of a quick summary of recent lattice computations related to confinement while the second examines the ideas of dynamical mass generation in the context of strong interaction. The connection between symmetry breaking and phase transition will be explored. Finally, I comment on how a detailed study of the phase transition from hadronic matter to a plasma of deconfined quarks and gluons, can improve our understanding of the cooling history of the early Universe.

Jarek Gołembiewski

Scaling of the velocity distribution function in flow through porous media

Several reports on velocity distribution function in porous media flow can be found. Depending on system configuration, Gaussian or exponential scaling was observed. At the same time other research showed that velocity distribution vary significantly with porosity. As some of available results appear to be rather inconsistent, I investigated velocity distribution in stochastically generated porous media. Thus some of my recent observation will be presented.

Prof. dr hab. David Blaschke (IFT)

Generalized Beth--Uhlenbeck formulas from the $Phi-$derivable approach in 2-loop approximation

A dense fermion system with strong two-particle correlations (bound and scattering states = composite bosons) is considered within the Phi-derivable approach to the thermodynamic potential. It is shown that in the two-loop approximation for the Phi-functional of this fermion-composite boson system important cancellations hold which are one key element in the proof that the thermodynamic potential takes the form of a generalized Beth-Uhlenbeck formula. The other element are generalized optical theorems. It is shown that generalized Beth-Uhlenbeck formulas also hold for the other thermodynamic functions (entropy, density) which all assume the generic form of an energy-momentum integral over a statistical distribution function multiplied with a unique spectral density. In the near mass-shell limit, contrary to na"{i}ve expectations, the latter reduces not to a Lorentzian but rather to a so-called "squared Lorentzian" shape. The developed formalism extends the validity of the Beth-Uhlenbeck approach beyond the low-density limit. It includes the Mott-dissociation of bound states in accordance with the Levinson theorem and the selfconsistent backreaction of the correlations to the propagation of the elementary fermions.

dr Janusz Szwabiński

Physics of food webs

Combining physics with ecology may seem strange at first sight. Ecology is dealing with the structure and the functioning of ecosystems. In contrast, physics is perceived as a science branch being quite successful in the description of the building blocks of matter. However, there are some similarities between these two disciplines. For instance, they both deal with systems consisting of many interacting elements and employ similar mathematical methods. As a result, interdisciplinary studies at the intersection of these two fields are more and more popular. After a short introduction into ecology, in this talk I will present some results of my recent studies on food webs and their stability.

Tomasz Trześniewski

The kappa-⁠Carroll particle from 3d gravity

Classical gravity in 2+1 dimensions can be formulated as the Chern-Simons theory with a local isometry group as the gauge group. Point particles may be coupled to this theory in a natural way. In principle one can then integrate out the gravitational degrees of freedom and obtain the effective particle action but in the case of de Sitter space it is rather difficult. On the other hand, de Sitter gauge group locally factorizes into the Lorentz group and the group $AN(2)$. For vanishing cosmological constant, corresponding to the flattening of the AN(2) component one recovers a particle in flat spacetime and with the momentum space given by the Lorentz group. It turns out that if one instead flattens the Lorentz component it leads to the ultrarelativistic particle solution, known as the Carroll particle but with the AN(2) momentum space. Interestingly, the AN(2) group is related to the so-called three-dimensional kappa-Poincare algebra, a well-studied example of deformations of relativistic symmetries which hypothetically arise in the quantization of gravity.

Jakub Poła

Application of GPU technology to OpenFOAM simuilations

Modern computational problems require a lot of computing resources. Serial processing are things in the past due to its inefficiency. Physical constraints put the limit on the CPU frequencies therefore the technology vendors switched into parallel architectures by adding more cores into processor. One way to accelerate calculations is to take advantage of shared memory and mu HPC systems based on CPU. The workload is divided between available cores thanks to which the solution can be obtained faster. The alternative way is to utilize the computational potential of modern GPU which performance is much higher compared to CPU. During the talk I will describe the two ideas showing how to involve the GPU into OpenFOAM suite, by presenting SpeedIT and SpeedIT Flow applications.

Cezary Juszczak

Electron scattering in nuwro

I will summarize the current status of the project of implementing the electron interactions in nuwro with emphasis put in the elastic scattering.

Dr. Craig Heinke (University of Alberta, Canada)

Using Thermal Emission from Neutron Stars to Constrain their Interiors

Thermal X-rays from the surface of neutron stars reveal crucial information about the surfaces and interiors of these dense stars.  I will explain our understanding of thermal emission from low-magnetic-field neutron stars. I will give illustrations of how we can use this thermal emission to understand the cooling of young and old neutron stars, including the Cas A neutron star (which seems to show evidence of a superfluid transition in its core).  Finally, I will discuss efforts to constrain the neutron star radius, through studying thermonuclear flashes, and from studying quiet neutron stars between accretion episodes in globular clusters, including new results. 

Dr Pok Man Lo, University of Wroclaw

Thermodynamics of Broad Resonances

In this talk we discuss the physics of the lightest resonances of QCD, i.e. the sigma and kappa mesons. These resonances are so broad that the standard Breit–Wigner dispersive analysis can not be applied. We motivate a theoretical analysis of the experimental phase shift data on pion-pion and pion-Kaon scattering. This allows us to explore the effects of broad resonances on thermodynamics. We also examine the role of chiral symmetry breaking in describing these phenomena by comparing different theoretical approaches, including the chiral effective model and lattice calculations.

Prof. David Blaschke, IFT, University of Wroclaw

Introduction to Heavy ​Ion Collisions and Matter under Extreme Conditions VIII

This is the eighth seminar/lecture talk performed within the monographic lecture course run by D. Blaschke, K. Redlich, and L.Turko. The course is devoted to master students, PhD students and all interested in the subject. More details in: http://panoramix.ift.uni.wroc.pl/pluginfile.php/10955/mod_resource/content/2/Monografic_Lecture_HIC 2015.pdf

Joanna Sobczyk

Lepton-nucleus scattering

During my talk I will make a brief introduction to the problem of lepton-nucleus scattering, motivated by recent experiments with neutrino flux. I will shortly describe language in which nuclei models are expressed (nuclear many body theory) and approximations that are commonly used.

Paweł Przewłocki (Narodowe Centrum Badań Jądrowych)

Experiments studying neutrino oscillations: news and future ideas

During the seminar I will discuss recent results related to neutrino oscillations and the most important challenges that neutrino physicists are currently facing. I will also talk about future experiments that will try to answer numerous important questions, such as what is the neutrino mass hierarchy or whether the CP symmetry is broken in the neutrino sector.

Dr. Giacomo Rosati

Relative locality at the Planck scale

In this seminar I introduce the possibility for the notion of absolutness of locality to be relaxed at the Planck scale, the scale at which quantum gravity effects are supposed to be relevant. Several approaches to quantum gravity suggest that, at such scale, spacetime should exhibit some nontrivial structure, and that relativistic symmetries should be modified. Relativity of locality is a general feature for theories with deformed relativistic symmetries, in which the scale of deformation (the Planck scale) plays the role of a relativistic invariant, and no preferred frame exists.

Dr. Matthias Hempel, University of Basel, Switzerland

Clusters and phase transitions in the supernova EoS

The low density EoS of supernova matter is governed by the nuclear liquid-gas phase transition, that is also connected to cluster formation. At high densities, a phase transition to deconfined quark matter can occur. I will discuss some basic aspects of these two phase transition, how they can be implemented in supernova simulations, and the possible effects they can have on the supernova dynamics.

Prof. David Blaschke, IFT, University of Wroclaw

Introduction to Heavy ­Ion Collisions and Matter under Extreme Conditions VII

This is the seventh seminar/lecture talk performed within the monographic lecture course run by D. Blaschke, K. Redlich, and L.Turko. The course is devoted to master students, PhD students and all interested in the subject. More details in: http://panoramix.ift.uni.wroc.pl/pluginfile.php/10955/mod_resource/content/2/Monografic_Lecture_HIC­ 2015.pdf

prof. Aleksander Iwanow (Instytut Matematyczny)

Struktury ciągłe obwodów kwantowych

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Kajetan Niewczas

Oddziaływania neutrin na skorelowanych parach nukleonów w eksperymencie ArgoNeuT.

Podczas seminarium zostanie omówiona publikacja ArgoNeuT Collaboration dotycząca wykrywania przeciwnie skierowanych par proton-proton powstałych w wyniku rozpraszania neutrin na tarczy argonowej. W pracy zaproponowano odważną tezę dotyczącą rekonstrukcji oddziaływań na skorelowanych parach neutron-proton. Podana formuła oraz dane eksperymentalne zostaną skonfrontowane z wynikami symulacji NuWro.

prof. dr hab. Jacek A. Majewski (Wydział Fizyki UW)

Inżynieria chemiczna własności fizycznych grafenu

Grafen stał się w ostatnich latach szeroko badanym materiałem o rozległych perspektywach różnych zastosowań. Niezwykłe własności elektryczne i elastyczne grafenu czynią go obiecującym kandydatem do stworzenia przyszłościowej elastycznej elektroniki, niemniej jednak na przeszkodzie stoi zerowa przerwa grafenu. W referacie zaprezentuję przewidywania teoretyczne, które pokazują, że poprzez funcjonalizację grafenu można otrzymać układy z przerwą energetyczną a jednocześnie o bardzo dobrych własnościach elastycznych. Pokażę również, jak zmieniają się charakterystyki prądowo-napięciowe oraz rozszczepienia spinowe pasm energetycznych (określające czas relaksacji spinowej) w funkcjonalizowanym grafenie. Przewidywania teoretyczne są oparte na rachunkach ab initio w formalizmie funkcjonału gęstości.

Dr Jakub Jankowski,Jagiellonian University, Cracow

Conformal defects in Supergravity

We construct numerically gravitational duals of theories deformed by localized Dirac delta sources for scalar operators both at zero and at finite temperature. We find that requiring that the backreacted geometry preserves the original scale invariance of the source uniquely determines the potential for the scalar field to be the one found in a certain Kaluza-Klein compactification of 11D supergravity. This result is obtained using an efficient perturbative expansion of the backreacted background at zero temperature and is confirmed by a direct numerical computation. Numerical solutions at finite temperatures are obtained and a detailed discussion of the numerical approach to the treatment of the Dirac delta sources is presented. The physics of defect configurations is illustrated with a calculation of entanglement entropy.

Prof. David Blaschke, IFT, University of Wroclaw

Introduction to Heavy-Ion Collisions and Matter under Extreme Conditions VI

This is the sixth seminar/lecture talk performed within the monographic lecture course run by D. Blaschke, K. Redlich. The course is devoted to master students, PhD students and all interested in the subject. More details in: http://panoramix.ift.uni.wroc.pl/pluginfile.php/10955/mod_resource/content/2/Monografic_Lecture_HIC-2015.pdf

Wielki Piątek - nie ma seminarium

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Jakub Żmuda

O rekonstrukcji oddziaływań neutrin na skorelowanych nukleonach na podstawie danych z eksperymentu ArgoNeuT oraz symulacji NuWro

Kontynuacja poprzedniego seminarium.

Prof. David Blaschke, IFT, Uniwersity of Wroclaw

Neutrino emissivities and bulk viscosity in neutral two flavor quark matter

We study thermodynamic and transport properties for the isotropic color-spin-locking (iso-CSL) superconducting quark matter phase under compact star constraints within a NJL-type chiral quark model. We present results for the iso-CSL direct URCA emissivities and bulk viscosities, which fulfil the constraints on quark matter derived from cooling and rotational evolution of compact stars.

Prof. David Blaschke, IFT, University of Wroclaw

Introduction to Heavy-Ion Collisions and Matter under Extreme Conditions V

This is the fifth seminar/lecture talk performed within the monographic lecture course run by D. Blaschke, K. Redlich. The course is devoted to master students, PhD students and all interested in the subject. More details in: http://panoramix.ift.uni.wroc.pl/pluginfile.php/10955/mod_resource/content/2/Monografic_Lecture_HIC-2015.pdf

Dr Andrej Radzhabov (Institute for System Dynamics and Control Theory SB RAS, Irkutsk)

Hadronic light-by-light contribution to muon anomalous magnetic moment of muon

The electron and muon anomalous magnetic moments (AMM) are measured in experiments and studied  in the Standard Model (SM) with the highest precision accessible in particle physics. The comparison of the measured quantity with the SM prediction for the electron AMM provides the best determination of the fine structure constant. The muon AMM is more sensitive to the appearance of possible effects beyond SM. We present the calculations of hadronic light-by-light scattering contribution to the AMM of muon in the  framework of the nonlocal chiral quark model. Our result leads to the 2.4 sigma difference in values of AMM of muon between the standard model and the experiment.

Aneta Wojnar

Lie symmetries techniques in application to cosmology: working examples

I will shortly discuss advantages of Lie symmetries in two cosmological models: FRLW and Bianchi ones in a framework of Extended Theories of Gravity.

Aleksandr Dubinin

Mott-⁠hadron resonance gas in effective QCD and a "toy" model

A quark-meson-diquark plasma is considered within the PNJL model for dynamical chiral symmetry breaking and restoration in quark matter. Based on a generalized Beth-Uhlenbeck approach to mesons and diquarks we present the thermodynamics of this system including the Mott dissociation of mesons and diquarks at finite temperature. On this basis we construct a "toy" model for the generic behaviour of hadron masses and phase shifts at finite temperature which shares basic features with a recently developed PNJL model for correlations in quark matter. We obtain the transition between a hadron resonance gas phase and the quark gluon plasma in the spirit of the generalized Beth-Uhlenbeck approach where the Mott dissociation of hadrons is encoded in the hadronic phase shifts. In this seminar I will compare our two models and explain the input of quark masses in the "toy" model.

Jakub Żmuda

O możliwości faktoryzacji przekroju czynnego pochodzącego z wybicia dwóch nukelonów

Omówiona zostanie niedawna publikacja grupy Cosyle, Cosyn, Ryckebusch i Vanhalst, w której przedstawiono możliwość dokonania fakoryzacji procesu wybicia dwóch nukleonów z jądra w procesie rozpraszania elektronów. Okazuje się, że przekrój czynny na ten proces jest proporcjonalny do warunkowego rozkładu pędów w układzie środka masy blisko związanych par nukleonów. Funkcja faktoryzacyjna jest też w znacznej mierze niewrażliwa na oddziaływania stanów końcowych. Przy wzrastającym zainteresowaniu tego typu procesami w środowisku neutrinowym praca ta rzuca także nowe światło możliwości ich opisu i pomiarów.

prof. dr hab. inż. Arkadiusz Wójs (KFT PWr)

Złożone fermiony i topologiczne ciecze kwantowe ***** Composite fermions & topological quantum liquids

Fractional quantum Hall effect (FQHE) involves condensation of two dimensional electrons in a high magnetic field B into various topological quantum liquids at different Landau level (LL) filling fractions nu. The key concept in the FQHE theory is emergence of “composite fermions” (CFs) – electrons binding an even number (2p) of vortices of the many-body wave function. The CFs are collective, topological particles which can loosely be viewed as e-charged fermions in a reduced magnetic field B*. Most of about 75 filling factors at which FQHE has been observed so far belong to the so-called Jain sequence nu=n/(2pn±1) which can be understood in terms of essentially free CFs filling an integral number n of effective Landau-like “Λ levels” (ΛLs). But there are also a few others, like nu=5/2 or 4/11, crucially dependent on complex residual interaction among the CFs, and remaining the subject of intensive experimental and theoretical investigation. In this lecture, I will present the electron liquids of FQHE in the broader context of topological states of matter, introduce the grand concept of CFs, apply it to the puzzling states represented by nu=5/2 and 4/11, and review our recent (numerical) studies giving new insight into the microscopic origin of their incompressibility.

Prof. dr hab. Zbigniew Haba

Człon kosmologiczny i pole magnetyczne w kosmologii (Cosmological term and magnetic field in cosmology)

Dr H. Grigorian. JINR Dubna, Russia

Cooling of neutron stars and hybrid stars with a stiff hadronic EoS

Within the "nuclear medium cooling" scenario of neutron stars all reliably known temperature - age data can be comfortably explained by a set of cooling curves obtained by variation of the star mass within the range of typical observed masses. The recent measurements of the high masses of the pulsars PSR J1614-2230 and PSR J0348-0432 on the one hand and the low masses for PSR J0737-3039B and the companion of PSR J1756-2251 on the other provide independent proof for the existence of neutron stars with masses in a broad range from 1.2 to 2 M⊙. The values M>2 M⊙ call for sufficiently stiff equations of state for neutron star matter. We investigate the response of the set of neutron star cooling curves to a stiffening of the nuclear equation of state so that maximum masses of about 2.4 M⊙ would be accessible and to a deconfinement phase transition from such stiff nuclear matter in the outer core to colour superconducting quark matter in the inner core. Without readjustment of cooling inputs the mass range required to cover all cooling data for the stiff DD2 equation of state should include masses of 2.426 M⊙ for describing the fast cooling of CasA while the existence of a quark matter core accelerates the cooling so that CasA cooling data are described with a hybrid star of mass 1.674 M⊙

Prof. David Blaschke, IFT, University of Wroclaw

Introduction to Heavy-Ion Collisions and Matter under Extreme Conditions IV

This is the fourth seminar/lecture talk performed within the monographic lecture course run by D. Blaschke, K. Redlich. The course is devoted to master students, PhD students and all interested in the subject. More details in: http://panoramix.ift.uni.wroc.pl/pluginfile.php/10955/mod_resource/content/2/Monografic_Lecture_HIC-2015.pdf

Mariusz Adamski

From Quantum Geometry to Phase Transitions

I will briefly introduce some quantum-geometrical concepts, such as fidelity and quantum geometric tensor, and show how they can be used in the studies of quantum phase transitions. Next, I will skim through some of my own results in a particular two dimensional model, which can be regarded as a mean field approximation to the so-called t-J model, postulated as the one describing high temperature superconductivity (at last in cuprates). We will see how those geometric methods work in practice, which will also enable us to postulate some "heuristic" and not-so-heuristic rules that govern this approach.

mgr Daniel Zabłocki (obrona pracy doktorskiej)

Meson and diquark correlations in a chiral model for normal and color superconducting quark matter

Szanowni Państwo, na skutek pewnych nieścisłości mogły pojawić się wątpliwości dotyczące godziny obrony. Chciałem potwierdzić, że wcześniej ogłoszona godzina 12.15 pozostaje w mocy.

prof. D. Ebert, Humboldt-Universitaet, Berlin, Germany

Strong decays of vector mesons to pseudoscalar mesons in the relativistic quark model

Strong decays of vector mesons to pseudoscalar mesons are considered in the framework of the microscopic decay mechanism and the relativistic quark model based on the quasipotential approach. The quark-aniquark potential is employed as the source of the q-qbar pair creation. The calculated rates of strong decays of light and heavy-light mesons and heavy quarkonia agree well with available experimental data.

prof. Ludwik Turko, IFT, University of Wroclaw

Introduction to Heavy-Ion Collisions and Matter under Extreme Conditions III

This is the second seminar talk performed within the monographic lecture course run by D. Blaschke, K. Redlich. The lecture is devoted to master students, PhD students and all interested in the subject. More details in: http://panoramix.ift.uni.wroc.pl/pluginfile.php/10955/mod_resource/content/2/Monografic_Lecture_HIC-2015.pdf

Prof. dr Dietmar Ebert, Uniwersytet Humboldta w Berlinie

Effective Quantum Field Theory and Graphene

This is a pedagogical introduction into an "Effective QFT" - description of graphene. The lecture explains the "pseudospin" (sublattice) and "valley" (Dirac point) degrees of freedom of electrons of the graphene lattice. Then, using a tight-⁠⁠binding model, the effective Dirac Hamiltonian of quasirelativistic massless electrons is derived. On this basis, the so-⁠⁠called Klein paradox and the chiral symmetry breaking of the U(2) valley-⁠⁠sublattice symmetry are discussed. Finally, a pseudopotential model for defects in graphene is presented and its relation to defect-⁠⁠induced gauge fields is discussed.

Prof. dr Dietmar Ebert, Uniwersytet Humboldta w Berlinie

Integer/Fractional Quantum Hall Effect (IQHE/FQHE) and Graphene

This is an introductory lecture for the IQHE based on Landau quantization of free electrons in a magnetic field and for the FQHE resulting from electron correlations due to dominant Coulomb interactions. First, the Landau quantization of the nonrelativistic Schroedinger Hamiltonian and the effective Dirac-like Hamiltonian is reviewed and the resulting energy spectra of electrons are presented. Next, the quantization of the Hall conductivity and its relation to topological invariants and the first Chern number are discussed. In particular, the analogy to the Gauss-⁠Bonnet theorem in geometry is demonstrated by using the concepts of the Berry phase and the Berry connection/⁠curvature. Notice also that the FQHE inspired the introduction of new composite objects-⁠-⁠"Composite Fermions (CF)"-⁠-⁠which are electrons with attached flux quanta (vortices). It will be shown that the CF of the FQHE can be described by an effective Outline: applications of AdS_4/⁠CFT_3 duality to FQHE, topological insulators and superconductors.

Dr. Jens Berdermann (German Aerospace Center - DLR , Neustrelitz)

Space Weather and its influence on the Ionosphere

The Ionosphere group of the institute of communication and navigation at DLR is involved in ionospheric monitoring, modelling and studying the ionospheric impact on radio signals since many years. The ionosphere is a significant error source of the Global Navigation Satellite Systems (GNSS) error budget and can induce range errors from a few meters to tens of meters at the zenith or during strong geomagnetic storm conditions. Therefore a very large amount of ionospheric data has been captured, processed as well as archived since 1995 at DLR Neustrelitz. The captured data is being used for ionospheric research including modelling and characterization of ionospheric parameters and effects. This talk provides an overview of DLR’s ongoing ionospheric research activities also giving an introduction to related measurement facilities at DLR, like the high rate GPS receiver scintillation network, the ACE/DSCOVR reception antenna and the high-resolution ionospheric real-time detector setup for solar flares. Starting in 2004 DLR has developed the Space Weather Application Center Ionosphere (SWACI) in order to provide relevant space weather information, in particular now- and forecast of the ionospheric state to the public. I will also give an overview about the recent status of the IMPC and our application oriented research towards even more sophisticated methods for spatial and temporal high-resolution reconstruction, modeling and forecasts of the ionosphere.

Dr Olaf Kaczmarek, University of Bielefeld, Germany

Recent developments in Lattice QCD studies for transport coefficients and quarkonia in the QGP

I will report on a lattice investigation of heavy quark momentum diffusion within pure SU(3) plasma above the deconfinement transition, with quarks treated to leading order in the heavy mass expansion. We measure the relevant ``colour-electric'' Euclidean correlator and based on several lattice spacings perform the continuum extrapolation. This will allow for a determination of the relevant transport coefficient in the continuum. Furthermore new results for charmonium and bottomonium states in the QGP will be presented.

prof. Ludwik Turko, IFT, University of Wroclaw

Introduction to Heavy-Ion Collisions and Matter under Extreme Conditions II

This is the second seminar talk performed within the monographic lecture course run by D. Blaschke, K. Redlich. The lecture is devoted to master students, PhD students and all interested in the subject. More details in: http://panoramix.ift.uni.wroc.pl/pluginfile.php/10955/mod_resource/content/2/Monografic_Lecture_HIC-2015.pdf

Łukasz Juchnowski

Particle pair creation in strong laser fields and the QED vacuum excitation. Some new results.

During seminar I will describe our recent result on dynamical pair production. Moreover I will briefly introduce physics of Schwinger effect. The talk will be base on our new papers arXiv:1412.7470, arXiv:1412.6372.

dr Thomas Klähn, IFT - University of Wroclaw

Bag model revisited

The bag model is probably the most simple model to describe the equation of state of dense quark matter one can think of. A significantly more sophisticated approach to dense quark matter is provided by the Dyson-Schwinger formalism. I will explain briefly, how the bag model can be understood within this framework, what it misses and how it can be extended without loosing simplicity. I will make a few additional remarks regarding the 'standard' Maxwell phase transition construction and it's applicability.

prof. Ludwik Turko

Introduction to Heavy-Ion Collisions and Matter under Extreme Conditions

This is the first of the monographic lecture course run by D. Blaschke, K. Redlich, L. Turko. The lecture is devoted to master students, PhD students and all interested in the subject. More details in: http://www.wfa.uni.wroc.pl/pub/content/3552/files/Introduction%20to%20Heavy-Ion%20Collisions%20and%20Matter%20under%20Extreme%20Conditions.pdf

dr hab. Piotr Ługiewicz

Poza granicami twierdzenia Earnshawa: lewitująca żaba

Samoczynne unoszenie się obiektów zawsze budzi emocje, zwłaszcza, gdy odnosi się do organizmów żywych, w tym przede wszystkim do człowieka. Zostaną omówione teoretyczne podstawy zjawiska lewitacji z udziałem statycznego pola magnetycznego. Przedstawiony zostanie krótki rys historyczny sięgający twierdzenia Earnshawa z pierwszej połowy XIX w. (wraz z elementarnym dowodem tego twierdzenia). Zostanie również omówione doświadczenie, w którym doprowadzono organizm zwierzęcy (małą żabkę) do stanu lewitacji z udziałem stałego pola magnetycznego.

dr Chihiro Sasaki, Frankfurt Institute for Advanced Studies (FIAS), Germany

Charm fluctuations and chiral transition

Thermal fluctuations and correlations between the light and heavy-light mesons are explored within a chiral effective theory implementing heavy quark symmetry. We show, that various heavy-light flavor correlations indicate a remnant of the chiral criticality in a narrow range of temperature where the chiral susceptibility exhibits a peak structure. The onset of the chiral crossover, in the heavy-light flavor correlations, is therefore independent from the light flavors. This indicates that the fluctuations carried by strange charmed mesons can also be used to identify the chiral crossover, which is dominated by the non-strange light quark dynamics.

Prof. dr hab. Ludwik Turko

The critical behavior of hadronic matter: a comparison of lattice and bootstrap model calculations

Hagedorn statistical bootstrap model and the related concept of the limiting temperature begun the discussion about phase transitions in the hadronic matter. This was also the origin of the quark-gluon plasma concept. We discuss here to which extend lattice studies of QCD critical behavior at non-zero chemical potential are comparable with the statistical bootstrap model calculations.

Dr. Anatoly Panferov (Saratov State University)

Сomputer modeling of dynamic Schwinger effect: problems and opportunities

We consider the problem of pair creation in time-dependent strong external fields within a kinetic equation approach. Different types of time dependence of model laser pulses and their relation to the distribution function of produced particles are discussed. Special attention is paid to the subtleties of the numerical solution of the kinetic equation with time-dependent non-Markovian source term.

dr Francesco Cianfrani

Quantum Cosmology from canonical Quantum Gravity

I will review the most successful canonical approaches towards Quantum Gravity, namely Wheeler-DeWitt quantization and Loop Quantum Gravity, in connection with the definition of a quantum theory for the Universe. I will outline how recent developments allow us to construct a proper phenomenology, which may be tested in observational cosmology.

mgr inż. Krzysztof Domino, Politechnika Śląska w Gliwicach, Instytut Fizyki

Zastosowanie Funkcji Kopuły oraz wykładnika Hursta do oceny ryzyka inwestycyjnego

Podczas referatu zostanie omówione wykorzystanie funkcji Kopuły do analizy dwuskładnikowych portfeli inwestycyjnych składających się z papierów wartościowych notowanych na GPW w Warszawie oraz innych światowych giełdach papierów wartościowych (w Nowym Jorku, Londynie, Sydney, Frankfurcie oraz Hong Kongu).

prof. David Blaschke (JINR BLTP and Univ. Wroclaw, Poland)

Quantum flavor kinetics and chemical freeze-out

We present current status of a quantum kinetic formulation of the chemical equilibration process in dense hadronic matter at the hadronization transition. Delocalization of hadron wave functions at the Mott-Anderson transition (where their binding energies vanish) lead to a divergence of scattering lengths and critical enhancement of earrangement collisions between hadrons. We exemplify this for different meson-meson scattering processes from light (pi-pi scattering) to heavy flavors (charmonium dissociation). On this basis we suggest that chemical freeze-out has to be correlated with (partial) chiral symmetry restoration.

Aneta Wojnar

Invariant solutions and Noether symmetries in Hybrid Gravity

Symmetries play an important role in physics and, in particular, the Noether symmetry is a useful tool to select models motivated at a fundamental level, and it is useful in finding exact solutions for a specific Lagrangian. In this work, we consider the application of point symmetries in the recently proposed hybrid metric-Palatini gravitational theory in order to select the f(R) function and to find analytical solutions of the field equations and of the Wheeler-DeWitt (WDW) equation in quantum cosmology.

prof. dr hab. Marek Besiada (IF UŚl)

Primordial gravitational waves - at gates of a new era

My seminar will be focused on the detection of B modes in Cosmic Microvawe Background Radiation (CMBR) reported last year. If finally confirmed, this discovery would confirm the last prediction of the inflationary paradigm - the existence of primordial gravitational waves i.e. the tensor metric perturbations generated by amplified quantum fluctuations of the inflaton scalar field. It would also open up a unique window to very early universe. I will start with brief introduction to modern inflationary cosmology and its successful predictions concerning primordial fluctuations anisotropy and CMBR polarization patterns. Then I will review the discovery of primordial gravitational waves announced by BICEP2, its essence and uncertainties as well as its importance for theories of very early Universe and the challenges it poses for both theory and CMBR observations. My talk will be concluded with a short description of the planned next generation mission CoRE+ supported also by Polish scientific community.

prof. dr hab. Agnieszka Zalewska (IFJ PAN Kraków)

CERN: Highlights of research, technology and education

CERN, the world’s leading laboratory in particle physics, celebrated its 60th anniversary last year. The milestones and the variety of its research will be presented as well as some implications for the development of technology and educational activities.

mgr Łukasz Juchnowski - IFT UWr

The dynamical Schwinger effect in the electron-positron plasma

We study the dynamical Schwinger effect in the vacuum excitation of the electron-positron plasma under action of a "laser pulse" of the simplest configuration: a linearly polarized,time-dependent and spatially homogeneous electric field. Methodical basis of this investigation is the kinetic equation which is an exact consequence of the basic equations of motion of QED in the considered field model. In the present work we investigate some features of the residual electron- positron plasma and the transient process of its formation. Moreover we compare predictions on the basis of different WKB-type approximations with our results. Such a comparison demonstrates a considerable divergence results in strong non-stationary fields.

Aleksandr Dubinin

Mott-hadron resonance gas

We present an effective model for the generic behaviour of hadron masses and phase shifts at finite temperature which shares basic features with recent developments within the PNJL model for correlations in quark matter. On this basis we obtain the transition between a hadron resonance gas phase and the quark gluon plasma in the spirit of the generalized Beth-Uhlenbeck approach where the Mott dissociation of hadrons is encoded in the hadronic phase shifts.

mgr Marek Miller

Dodatnie odzworowania ekstremalne na algebrach macierzy: stabilne podprzestrzenie i nowe przykłady.

Podczas wykładu postaram się przybliżyć najnowsze wyniki zebrane w arXiv:1412.7469. Tematem wystąpienia będą ekstremalne odwzorowania dodatnie na algebrach macierzy. Ustalenie istnienia podprzestrzeni stabilnych ze względu na wielokrotne składanie dla szerokiej klasy takich odwzorowań stanie się punktem wyjścia do sformułowania twierdzenia wyliczającego wszystkie możliwe postaci podprzestrzeni stabilnych w najprostszym nierozpoznanym przypadku algebry macierzy rozmiaru 3x3. Co interesujące, jedna z możliwości będzie wymagać podania nowego przykładu odwzorowania dodatniego oraz udowodnienia jego ekstremalności. Elementarny dowód tego faktu zajmie drugą, bardziej techniczną cześć wykładu, którego czas trwania szacuję na około 60 min.

prof. dr hab. Piotr M. Hajac (IM PAN Warszawa/University of New Brunswick)

There and back again: from the Borsuk-Ulam theorem to quantum spaces

Assuming that both temperature and pressure are continuous functions, we can conclude that there are always two antipodal points on Earth with exactly the same pressure and temperature. This is the two-dimensional version of the celebrated Borsuk-Ulam Theorem which states that for any continuous map from the n-dimensional sphere to n-dimensional real Euclidean space there is always a pair of antipodal points on the sphere that are identified by the map. Our quest to unravel topological mysteries in the Middle Earth of quantum spaces will begin with gentle preparations in the Shire of elementary topology. Then, after riding swiftly through the Rohan of C*-algebras and Gelfand-Naimark Theorems and carefully avoiding the Mordor of incomprehensible technicalities, we shall arrive in the Gondor of compact quantum groups acting on unital C*-algebras. It is therein that the generalized Borsuk-Ulam-type statements dwell waiting to be proven or disproven. Time permitting, we shall pay tribute to the ancient quantum group SUq(2), and show how the proven non-trivializability of the SUq(2)-principal instanton bundle is a special case of two different noncommutative Borsuk-Ulam-type conjectures. (Based on joint work with Paul F. Baum and Ludwik Dabrowski.)

Maciej Lewicki, Michał Naskręt - IFT UWr

Time projection chambers (TPC) in the experiment NA61/SHINE: 1.Calibration of TPC with pulser tool 2. Krypton calibration of TPC

1. The pulser tool is used to scan the electronic response of each pad in a TPC chamber. Sending a short electric pulse through all the pads can give us an information about an electronic gain and time delay. Therefore primary goal of the pulser calibration is to determine the time delay for each pad. In addition, the obtained data can be used for diagnostic purposes: finding dead pads, dead channels or front-end electronics. 2.Simulation of events in a TPC chamber through a decay of excited Krypton atoms gives us a spectrum, which is later fitted to the model spectrum of Krypton from a Monte-Carlo simulation. The data obtained in such a way serves us to determine malfunctioning electronics in TPC. Thanks to the krypton calibration we can determine channels and create a map of pad by pad gains. In my talk I will present an algorithm I developed and results I obtained for recent calibration runs.

dr hab. Grzegorz Kondrat

There and back again or between discrete and continuous percolation

The phenomenon of percolation belongs to canonical examples of phase transitions. Even though there are many differences between continuous and discrete versions, some deep connections between them exist and will be discussed. With the simple model of porous media as an example the new idea of discrete excluded volume theory will be introduced.

Kjetil Thøgersen (University of Oslo)

Direct modeling of particle suspensions

Modeling particle suspensions in incompressible fluids is of interest in fields ranging from crystal rich magmatic intrusions to swimming microbes and flow of proppant packings. This is a particularly challenging task when modeling the regime of large volume fractions, which is dominated by particle interactions. We present an adaptive unstructured finite element model for two-dimensional particle-laden flows at low Reynolds numbers, and show how the close particle interactions can be upscaled using Schur complements and lubrication theory. We then present a few examples of what the model is used for, including effective viscosity, shear induced mixing and particle dispersion.

Marek Miller

A new example of an extremal positive map

During my talk, I will show that a particular positive map of square matrices of size 3x3 is extremal, and will try to explain why such a modest result could still be considered important.

prof. dr hab. Tadeusz Domański (UMCS, Lublin)

Andreev and Majorana-type quasiparticles in nanoscopic systems

It is well known that the electronic states of isotropic superconductors are prohibited inside some characteristic energy window Delta ~ meV around the Fermi surface because of electron pairing. Similar property has been recently observed in various nanoscopic objects (e.g. molecules, nanowires, carbon nanotubes, self-assembled quantum dots) due to the proximity effect, where the penetrating Cooper pairs convert them into superconducting nanoislands. The proximized nanoobjects often reveal formation of the additional in-gap (subgap) bound states. These Andreev-Yu-Shiba-Rusinov quasiparticles appear always in pairs because they represent coherent superpositions of the particle and hole states. Under specific conditions (due to spin-orbit coupling and external magnetic field) some of the in-gap states may evolve into the Majorana-type quasiparticles. In fact, the first experimental signature of the zero-energy Majorana feature has been reported by the Dutch group from Delft using InSb wire deposited on the s-wave NbTiN superconductor [V. Mourik et al, Science 336, 1003 (2012)]. I shall give a survey on the recent intensive studies of the Andreev/Majorana quasiparticles in nanoscopic systems. I will also discuss some closely related studies on the Cooper pair splitters, where the released/depaired electrons preserve their quantum entanglement over macroscopic scales.

dr hab. Katarzyna Sznajd-Weron

Osobowość czy sytuacja - czy debata psychologiczna może wnieść coś nowego do modelowania agentowego i vice versa

Jarek Gołembiewski

Granty dla doktorantów, czyli o finansowaniu badań naukowych.

prof. dr hab. Ludwik Turko (IFT)

Particle in strong fields

Problems related to the description of particles bound by strong external fields are present on all levels of the theory - started from the classical, then quantum mechanical, then quantum field theoretical formulations. A number of new effects is then expected as spontaneous positron emission or an appearance of condensates. Short review of problems on different levels will be given.

Kolokwium habilitacyjne dr Piotra Ługiewicza

Zamknięte posiedzenie Rady IFT

Cezary Juszczak

Struktura powłokowa a wybicie kilku nukleonów w kaskadzie wewnątrz jądrowej

Na podstawie kilku prac grupy z Liege, omówię model jądra stosowany przez nich do opisu kaskady wewnątrz-jądrowej z dyskusją, które elementy można uwzględnić przy rozwoju nuwro.

dr Tomasz Paterek (Nanyang Technological University, National University of Singapore)

Strange law of quantum communication and a few words on research and studies at Singapore's NTU

This talk will comprise two parts. In the scientific part I will describe somewhat strange effect in which quantum entanglement between distant observers grows although no entanglement has ever been transmitted between them. The second part will be devoted to physics research and facilities at Nanyang Technological University (NTU) in Singapore and stipends it offers to PhD students. I hope this will be of interest to faculty members who would like to collaborate with Singapore's scientists as well as students who would like to pursue their postgraduate career at NTU.

dr Kenji Morita (Yukawa Institute in Kyoto)

Lambda-Lambda interaction from relativistic heavy ion collisions

We discuss how to extract Lambda-Lambda interaction from relativistic heavy ion collisions. We present a theoretical framework to disentangle several sources of Lambda-Lambda correlation and comparison with STAR data.

Katarzyna Suska

Charts DOS and DON'TS

Our next seminar: „Charts DOS and DON'TS” is attached to one of our previous subject about how to write a good paper. In this seminar we will setting some ground rules in plotting graphs. We will see how we shouldn't present our data in a good paper, and we will try to conclude how the perfect graph should look like.

Monireh Kabirnezhad (Narodowe Centrum Badań Jądrowych, Warszawa)

Multipole expansion in single pion production

Multipole expansion in non-resonant interaction of single pion production is used for studying resonant and non-resonant contributions and their interference. They will be reviewed technically, from a paper by D. Rein, and a general correction to the model, and a detailed treatment of the lepton mass are going to be discussed.

prof. dr hab. Detlef Hommel (IFD)

Nobel Prize in Physics 2014

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Joanna Sobczyk

If no (standard) Higgs then what?

Higgs particle has been a hot topic in the particle physics recently. Even though it was discovered 2 years ago, we still want to know more about its basic properties in order to look for the physics beyond Standrad Model. In my talk I will present some basic ideas standing behind Higgs physics (the Higgs mechanism). I will treat it as the starting point for the further searches of a strongly interacting theory responsible for the eletroweak symmetry breaking.

Jan Sobczyk

O problemach z opisem produkcji pionów w oddziaływaniach neutrin

Omówione będą stare i nowe trudności i problemy ze zrozumieniem produkcji pionów oddziaływaniach neutrin.

Profesor Helmut Satz

Tytuł doktora honoris causa dla profesora Helmuta Satza

Dnia 14 listopada 2014 roku, w dniu Święta Uniwersytetu, tytuł doktora honoris causa otrzyma wybitny fizyk prof. Helmut Satz z Uniwersytetu w Bielefeld, Niemcy. Uroczystość odbędzie się w Auli Leopoldyńskiej o godz. 11.00 Tytuł ten zostanie nadany na wniosek, który wypłynął z inicjatywy naszego Instytutu. Wszyscy pracownicy naukowi Instytutu, doktoranci oraz studenci są na uroczystość gorąco zaproszeni.

mgr Tomasz Golan

Modeling nuclear effects in NuWro Monte Carlo neutrino event generator (obrona pracy doktorskiej)

Głównym celem pracy doktorskiej było zbadanie efektów jądrowych w oddziaływaniach neutrin z jądrami atomowymi oraz ich implementacja w generatorze Monte Carlo NuWro. W rozprawie przedstawiono opis modeli fizycznych użytych w generatorze. Szczególny nacisk położony został na model oddziaływań stanów końcowych, który był przewodnim tematem badań. Uwzględnione zostały liczne efekty kwantowe, takie jak ruch Fermiego, blokowanie Pauliego, czy czas kształtowania, które towarzyszą propagacji cząstek przez jądro. Przewidywania generatora zostały skonfrontowane z danymi doświadczalnymi. Podsumowaniem pracy jest pełna analiza danych dla elastycznego rozpraszania neutrin na $CH_2$ przez prąd neutralny zmierzonych przez eksperyment MiniBooNE, wykonana przy użyciu generatora NuWro. ************** The main goal of the PhD thesis is the investigation of nuclear effects and the implementation of them into a neutrino Monte Carlo event generator NuWro. A description of physical models used in the generator is presented. Model of final state interactions is described in a more detailed way, as it was an essential part of the PhD thesis. Many quantum effects related to a propagation of particles through a nucleus, like Fermi motion, Pauli blocking, or formation zone, are taken into account. NuWro predictions are compared to experimental data and other generators results. Finally, a full analysis of the data for neutral current elastic neutrino scattering off $CH_2$ measured by the MiniBooNE experiment made using NuWro generator is presented. An influence of two-body current contribution on the results is investigated.

Dr David Edwin Alvarez Castillo

Supporting the existence of the QCD critical point by compact star observations

We present the argument that the observation of a gap in the mass-radius relationship for compact stars which proves the existence of a so-called third family (aka "mass twins") will imply that the $T=0$ equation of state of compact star matter exhibits a strong first order transition with a latent heat that satisfies $Deltaepsilon/epsilon_c > 0.6$. The observation of a disconnected branch (third family) of compact stars in the mass-radius diagram proves the existence of a CEP in QCD. Furthermore we show results of a Bayesian analysis (BA) using disjunct M-R constraints for extracting probability measures for cold, dense matter equations of state. In particular this study reveals that measuring radii of the neutron star twins has the potential to support the existence of a first order phase transition for compact star matter.

dr hab. G. Kondrat

Tam i z powrotem, czyli między perkolacją dyskretną a ciągłą

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Krzysztof Graczyk

Model Independence, Dispersion Approach and Nucleon Form-Factors

Dispersion methods in particle physics will be shortly introduced and their application to extraction of the electromagnetic and axial form factors of the nucleon will be reviewed.

Dzień rektorski - nie ma seminarium

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Aleksandr Dubinin (IFT)

Mott-hadron resonance gas and lattice QCD thermodynamics.

We present an effective model for the generic behavior of hadron masses and phase shifts at finite temperature which shares basic features with recent developments within the PNJL model for correlations in quark matter. On this basis we obtain the transition between a hadron resonance gas phase and the quark gluon plasma in the spirit of the generalized Beth-Uhlenbeck approach where the Mott dissociation of hadrons is encoded in the hadronic phase shifts. We find that the restriction to low-lying hadronic channels is justified by the rather low chiral transition temperature found in recent lattice QCD thermodynamics results.

źródło internetowe

Projekcja wykładu o neutrinach Borisa Kaysera

Wykład został wygłoszony podczas HCP 2013 summer school w CERN'ie.

Alexandra Friesen, JINR Dubna

Quark scattering off quarks and hadrons

The in-medium elastic scattering qq → qq, bar{q}q → bar{q}q and bar{q}bar{q} → bar{q}bar{q} is calculated within the two-flavor Polyakov-loop-extended Nambu-Jona-Lasinio model. The integral and differential quark-quark scattering, its energy and temperature dependence are considered and their flavor dependence is emphasized. The comparison with results of other approaches is presented. The consideration is implemented to the case of quark-pion scattering characterizing the interaction between quarks and hadrons in a kinetic multiphase treatment, and the first estimate of the quark-pion cross sections is given. A possible application of the obtained results to heavy ion collisions is shortly discussed.

Vaclav Zatloukal (Czech Technical University, Prague)

Local-time representation of path integrals

We derive a local-time path-integral representation of one-dimensional time-independent quantum-mechanical systems. In particular, we show how to rephrase the matrix elements of the Bloch density matrix as a path integral over x-dependent local-time profiles. The latter quantify the time that the sample paths x(t) in the Feynman path integral spend in the vicinity of an arbitrary point x. Generalization of the local-time representation that includes arbitrary functionals of the local time is also provided. We argue that the results obtained represent a powerful alternative to the traditional Feynman–Kac formula, particularly in the low temperature regimes.

Michał Marczenko

Klasyczny i kwantowy opis układów ze zmienną masą oraz ich supersymmetryzacja

Celem seminarium jest przedstawienie problematyki związanej z układami ze zmienną masą w kontekście zarówno mechaniki klasycznej, jak i kwantowej. Przedstawione zostanie uogólnienie opisu newtonowskiego, lagranżowskiego oraz hamiltonowskiego, a także rozszerzenie twierdzenia Noether dla przypadku układów o zmiennej masie. Omówiony zostanie również problem konstrukcji funkcji Lagrange’a oraz problem niejednoznaczonści jej wyboru. Jako przykład przedyskutowane zostaną dwa typowe układy o masie będącej funkcją położenia, przy użyciu metody faktoryzacji oraz zdeformowanej algebry Poissona na poziomie mechaniki klasycznej. Następnie omówione zostanie sformułowanie mechaniki kwantowej dla przypadku masy jako funkcji położenia, skupiając się na tzw. problemie niejednoznaczości uporządkowania operatorów. Jako ostatnie zagadnienie przedstawione zostanie sformułowanie supersymetrycznej mechaniki kwantowej oraz jej zastosowanie, jako narzędzia do rozwiązywania problemów ze zmienną masą.

Beata Kowal

Kwazielestyczne rozpraszanie elektronów na jądrach atomowych

Podczas prezentacji przedstawię wyniki, które uzyskałam w mojej pracy magisterskiej dotyczącej rozpraszania kwazielastycznego elektronów na jądrach atomowych. Przedstawię formuły na przekrój czynny w modelu globalnego i lokalnego gazu Fermiego. Pokażę sposób znalezienia tensora hadronowego dla związanego nukleonu przy użyciu metody de Foresta i wynikający z niej problem niezachowania prądu oraz omówię metody jego przywracania. Pokażę wykresy, które wygenerowałam.

prof. dr hab. David Blaschke

Mass-radius relations and quark matter in compact stars

The equation of state of dense neutron star matter uniquely determines the structure of compact stars through the solution of Tolman-Oppenheimer-Volkoff equations, providing in particular mass-radius relationships of spherically symmetric (slowly rotating) stars. The latter are, in principle, accessible to astophysical observations and can thus provide strong constraints to models of matter under extreme conditions. We summarize the present status of mass and radius measurements for compact stars and discuss a possibility to detect by them whether there exists a strong phase transition to quark matter in neutron star matter at high densities.

dr hab. Andrzej Wereszczyński (UJ)

Neutron stars and EoS of nuclear matter in the near-BPS Skyrme model

Using a low energy effective model of QCD - the near-BPS Skyrme model (which provides a very good description of nuclear binding energies) I will study neutron stars with the back reaction of gravity on the matter field fully taken into account. After fitting 2 parameters of the model in B=1 sector I will find neutron stars ($B_{max} sim 10^{57}$) with a very good agreement with observational data. I will compute EoS and show that nuclear matter becomes stiffer when mass of the star increases.

Jakub Poła

Zastosowanie technologii GPGPU w obliczeniowej dynamice płynów

Podczas prezentacji przedstawione zostaną wybrane aplikacje technologii GPGPU w obliczeniowej dynamice płynów. Na początku zaprezentuję wyniki pracy magisterskiej, w której badałem model gazu sieciowego Boltzmanna i możliwość akceleracji obliczeń przy użyciu technologii NVIDIA CUDA. Następnie omówię zalety oraz wady wynikające z wykorzystania kart graficznych w metodzie objętości skończonych. Przykłady zastosowań technologii GPGPU będą opierały się o projekty SpeedIT oraz SpeedIT Flow, których jestem współautorem.

Beata Kowal

Kwazielestyczne rozpraszanie elektronów na jądrach atomowych

Podczas prezentacji przedstawię wyniki, które uzyskałam w mojej pracy magisterskiej dotyczącej rozpraszania kwazielastycznego elektronów na jądrach atomowych. Przedstawię formuły na przekrój czynny w modelu globalnego i lokalnego gazu Fermiego. Pokażę sposób znalezienia tensora hadronowego dla związanego nukleonu przy użyciu metody de Foresta i wynikający z niej problem niezachowania prądu oraz omówię metody jego przywracania. Pokażę wykresy, które wygenerowałam.

dr hab. Lech Jakóbczyk

Kłopoty z kwantowym dyskordem

Po referacie krótkie spotkanie organizacyjne.

dr hab. Janusz Jędrzejewski, prof. nadzw.

Kwantowe przemiany fazowe i krytyczność w perspektywie kwantowej wierności ***** Quantum phase transitions and criticality; the quantum-fidelity perspective

Przedstawię kwantowe przemiany fazowe i kwantową krytyczność w opozycji do termicznych odpowiedników. Podam podstawowe charakterystyki kwantowych punktów krytycznych (KPK) i zilustruję wprowadzane idee na przykładzie dwóch modeli -- paradygmatów teorii przemian fazowych. Podam przykłady układów fizycznych, których własności fizyczne wyjaśnia się obecnością KPK. Przedstawię krótko nową metodę badania KPK, metodę kwantowej wierności, oraz ostatnio otrzymane za jej pomocą wyniki w modelach typu modelu BCS. Skomentuję użyteczność nowej metody. ***** Quantum phase transitions and quantum criticality will be introduced and contrasted with their thermal counterparts. In particular basic characteristics of quantum critical points (QCPs) will be defined. The ideas will be illustrated using two paradigmatic models of both kinds of phase transitions. Examples of physical systems, whose properties are believed to be a consequence of the existence of KPK, will be given. A novel method of investigating QCPs -- quantum fidelity method, and recent results obtained with this method in BCS-like (pairing) models, will be briefly presented and its usefulness discussed.

Jakub Poła

Zastosowanie technologii GPGPU w obliczeniowej dynamice płynów

Podczas prezentacji przedstawione zostaną wybrane aplikacje technologii GPGPU w obliczeniowej dynamice płynów. Na początku zaprezentuję wyniki pracy magisterskiej, w której badałem model gazu sieciowego Boltzmanna i możliwość akceleracji obliczeń przy użyciu technologii Nvidia CUDA. Następnie omówię zalety oraz wady wynikające z wykorzystania kart graficznych w metodzie objętości skończonych. Przykłady zastosowań technologii GPGPU będą opierały się o projekty SpeedIT oraz SpeedIT Flow, których jestem współautorem.

dr hab. Zbigniew Koza, prof. nadzw.

Współbieżność poza MPI: wielkie wyzwanie dla fizyki obliczeniowej ****** Parallelism Beyond MPI: A Great Challenge of Computational Physics

W ciągu ostatnich 15 lat komputery przeszły ewolucję, która wymaga zmiany sposobu myślenia o programowaniu. Podczas seminarium omówię istotę tej (r)ewolucji oraz jej wpływ na fizykę obliczeniową. ****** In the last 15 years the computer hardware has evolved so much that its programming requires a paradigm shift. During the seminar I will discuss the essence of this (r)evolution as well as its impact on computational physics.

Hong-Bo Deng (GSI, Bejing University)

Strong and EM decays of light and heavy-light meson in the effective chiral NJL model

Methods of calculations of transitions amplitudes for strong and electromagnetic decays of mesons within effective NJL model will be presented.

multiauthors

flash seminars - change!

Important change: due to important organizational reasons this flash seminar is shifted by one day: from Wednesday to Thursday. Sorry for all inconveniences :-(. 1. Sanjin Benic: "The equation of state of dense and warm QCD matter" 2. Kenji Morita: "Net baryon number probability distribution near chiral phase transition" 3. Alex Kaltenborn: "Exotic Nuclear Shapes in the 'Pasta' Phase of Matter in Neutron Stars" 4. Oliver Hamil: "Braking index of rotating magnetized pulsars"

Jan Sobczyk

Nowe kierunki w modelowaniu odziaływań neutrin

Referat (wygłoszony tydzień temu na konferencji Neutrino 2014 w Boston) zawiera obszerny wstęp z uzasadnieniem dlaczego omawiany kierunek badań jest ważny dla doświadczeń neutrinowych z "długą bazą". Głównym tematem jest zagadnienie tzw "prądu dwuciałowego" będące w ostatnich latach obiektem wielu dociekań tak teoretycznych jak i doświadczalnych.

prof. Zbigniew Haba

Big Bang i KTP ***** Big Bang and QFT

Omówię sukcesy i trudności w zastosowaniu klasycznej i kwantowej teorii pola do kosmologii. Przedstawię modele gorącego Wszechświata, inflacji i obecnej przyśpieszonej ekspansji. Opiszę przybliżenia i założenia wprowadzane przy konstrukcji takich modeli. ***** Successes and difficulties of the contemprorary cosmology are reviewed. It is pointed out that such a theory is a compilation of classical and quantum field theories. Problems with a smooth coexistence of such theories will be discussed.

Adam Strycharski

Konstrukcja i własności dualnego modelu Isinga dla dwuwymiarowego modelu Isinga z oddziaływaniem najbliższych i następnych sąsiadów na sieci prostokątnej

Symetrie dualności są dobrze zbadane dla wielu 2-d modeli Isinga z oddziaływaniem najbliższych sąsiadów. Dzięki nim można wyznaczyć ściśle temperatury krytyczne wielu modeli bez znajdowania ich sum stanów. Konstrukcje modeli dualnych opierają się na możliwości wprowadzenia sieci dualnej do sieci wyjściowej rozpatrywanego modelu, w którym występują jedynie oddziaływania najbliższych sąsiadów. Niestety te konstrukcje nie dają się przeprowadzić w przypadku gdy w modelu wyjściowym uwzględniamy krzyżujące się oddziaływania dalszych sąsiadów. Opiszę metodę konstrukcji modelu dualnego do modelu Isinga z oddziaływaniami najbliższych i dalszych sąsiadów, która bazuje na transformacjach podobieństwa macierzy przejścia wyjściowego modelu, a która nie wymaga wprowadzania pojęcia sieci dualnej. Otrzymany model dualny zawiera oddziaływania 2-spinowe a także oddziaływania 4-spinowe, które są obrazem oddziaływań następnych sąsiadów poprzez transformację dualności. Następnie przedstawię jakościowe wnioski dotyczące zachowania się temperatury krytycznej modelu dualnego w oparciu o analizę dwóch szczególnych granicznych przypadków, dla których można znaleźć ścisłe rozwiązanie. Niestety nie da się znaleźć sumy stanów dla tego modelu w ogólnym przypadku, dlatego w dalszej części referatu przedstawię wyniki numerycznej analizy krytycznych własności rozpatrywanego modelu. Przejście fazowe w modelach Isinga pojawia się gdy, dla temperatur poniżej temperatury krytycznej, maksymalna wartość własna macierzy przejścia staję się zdegenerowana. Przedstawię wyniki numeryczne analizy dwóch największych wartości własnych macierzy przejścia rozpatrywanego modelu dla sieci, w których w jednym kierunku mamy dowolną liczbę węzłów a w drugim liczba węzłów wynosi nie więcej niż 24. W tym granicznym przypadku trzeba diagonalizować macierze kwadratowe o wymiarze 224. Jest to granica możliwości naszego instytutowego klastra komputerowego. Numeryczna analiza potwierdza analityczne przewidywania. Na zakończenie przedstawię numeryczna analizę wykładników krytycznych rozważanego modelu.

Prof. Zbigniew Haba

Prawa strona równań Einsteina

Omówione zostaną różne postaci tensora energii-pędu, które mogą wystąpić w równaniach Einsteina i zależność rozwiązań od tensora energii-pędu.

prof. Chihiro Sasaki (Frankfurt Institute for Advanced Studies)

QCD Thermodynamics from Effective Field Theories

I will give a brief overview on QCD thermodynamics including recent developments from effective theory approach. The following selected issues will be discussed: interplay between confinement and dynamical chiral symmetry breaking, trace anomaly in hot/dense matter, hadrons near chiral symmetry restoration, embedding quark-hadron duality.

prof. Pavel Stovicek (Praha)

Orthogonal polynomials, Jacobi matrices and the moment problem. A survey of the general theory and selected new results

A brief survey of the theory of orthogonal polynomials is given including the fundamental recurrence relation and Favard's theorem, the Hamburger moment problem and its solution in terms of the Nevanlinna parametrization of probability measures in the indeterminate case, a relationship to the self-adjoint extensions of the associated Jacobi matrix and properties of the zeros of an orthogonal polynomial sequence. Furthermore, selected new results concerning a generalization of the Lommel polynomials are presented; a complete description can be found in the recent publication: F. Stampach, P. Stovicek: Orthogonal polynomials associated with Coulomb wave functions, J. Math. Anal. Appl. (2014), in press, available online, http://dx.doi.org/10.1016/j.jmaa.2014.04.049 .

dr Janusz Miśkiewicz

Potęgowy schemat klasyfikacji korelacji w zastosowaniach ekonofizycznych ***** Power law classification scheme of correlations in econophysics applications

Korelacje krzyżowe stanowią istotny element analizy danych, szczególnie tam, gdzie charakter oddziaływania nie jest jeszcze poznany. Należy zauważyć, że dominująca pozycję mają tutaj metody oparte na współczynniku Pearsona, który bada istnienie korelacji liniowych. W referacie zostanie przedstawiona alternatywna metoda oparta na potęgowym schemacie korelacji. Pozwala ona na rozróżnienie znacznie szerszej klasy zależności określając siłę i stabilność badanych zależności. ***** Analysis of cross-correlations is an important element of data analysis, particularly in systems were model of interactions among systems was not established. The Pearson correlation coefficient is the most popular choice in cross-correlation analysis. However, it verifies only the hypothesis if the correlations are linear. In the seminar the alternative method i.e. power law classification scheme will be presented. This method significantly extends the range of correlation types allowing to measure strength and stability of correlations.

Sebastian Szkoda

Metody zrównoleglania algorytmów automatów komórkowych

Podczas seminarium przedstawię aktualny stan moich prac. Skupię się na wysokowydajnym wykonywaniu obliczeń naukowych metodami automatów komórkowych, na przykładzie rozwijanego przeze mnie algorytmu FHP. Przedstawione technologie oraz pomysły na implementacje są oczywiście możliwe do wykorzystania w innych zagadnieniach naukowych.

prof. P. Hajac (Warszawa)

Free actions of compact quantum group on unital C*-algebras

Let F be a field, G a finite group, and Map(G,F) the Hopf algebra of all set-theoretic maps G -> F. If E is a finite field extension of F and G is its Galois group, the extension is Galois if and only if the canonical map resulting from viewing E as a Map(G,F)-comodule is an isomorphism. Similarly, a finite covering space is regular if and only if the analogous canonical map is an isomorphism. The main result to be presented in this talk is an extension of this point of view to arbitrary actions of compact quantum groups on unital C*-algebras. I will explain that such an action is free (in the sense of Ellwood) if and only if the canonical map (obtained using the underlying Hopf algebra of the compact quantum group) is an isomorphism. In particular, we are able to express the freeness of a compact Hausdorff topological group action on a compact Hausdorff topological space in algebraic terms. Also, we can apply the main result to noncommutative join constructions and coactions of discrete groups on unital C*-algebras. (Joint work with Paul F. Baum and Kenny De Commer.)

Joanna Sobczyk

Modele rozpraszania elektron-jądro

Podczas seminarium przedstawię kilka modeli używanych do opisu oddziaływania elektronu z jądrem atomowym w przybliżeniu IA (impulse approximation). Zaprezentowane zostaną różne formalizmy i używane przybliżenia oraz ich wpływ na przekrój czynny.

dr Arkadiusz Błaut

"BICEP2" and detection of relic gravitational waves

Inflationary cosmology explains the origin of primordial inhomogeneities of matter serving as initial conditions for the structure formation in the Universe. It predicts at the same time the primordial gravitational waves whose indirect detection announced BICEP2 experiment in March 2014. I will introduce the standard mechanism of generation of stochastic gravitational wave background and comment on methods and prospects of their direct detection in future gravitational wave interferometry in space.

Tomasz Trześniewski

On the Effective Dimension of Spacetime

In the recent decades the theoretical physics gave rise to many ideas which are challenging the long-standing concepts. Such propositions are especially numerous in the regime of the hypothetical quantum gravity. One example is the prediction that in the very small scales, presumably close to the Planck length/time, the effective dimension of spacetime can be different than 4. I will begin with the definitions of the Hausdorff and spectral dimension and then present the spectrum of results obtained in a variety of approaches to the quantum gravity. I will particularly concentrate on the models with the deformed relativistic symmetries and the associated curved momentum space.

Krzysztof Graczyk

Bayesian framework, neural networks and nucleon form factors

The review of the Bayesian approach for feed-forward neural networks will be given. The aim is to introduce the basis of the Bayesian statistics and then to show how to adopt this framework for feed-forward neural networks. As an application I will show the extraction of the electromagnetic proton form factors and two photon exchange correction from the elastic ep scattering data. The seminar will have rather informal character.

prof. Frank Schweitzer (Chair of Systems Design, ETH Zurich)

Success and Failure - A Complex Network Perspective

The last 15 years have brought important insights into the structure and the dynamics of complex networks, e.g., to characterize classes of degree distributions, importance of nodes, universal growth mechanisms, or cascading processes on networks. However, surprisingly little is known about the impact of such features on the performance of a system, on the global level, or its constituents (agents), on the local level. Hence, we need to link structure and dynamics with performance in a quantitative, empirically testable way. This means, for the global perspective we have to specify how network resilience or systemic risk depend on the structural properties of the system and the dynamics of the agents. For the local perspective, we have to understand the feedback between the network position of an agents and its future success or failure as an individual. Most importantly, these insights have to be developed to a degree that allows us to predict success and failure, both on the systemic and the agent's level. In the talk, I will provide examples of large-scale analyses of different social networks that allow us to obtain the insights requested.

dr Maciej Matyka

Rozkład prędkości płynu w ośrodku porowatym

Przedstawię cel i motywację badań nad rozkładem prędkości w transporcie płynu przez ośrodki o budowie porowatej. Ostatnie wyniki eksperymentalne (Phys. Rev. Lett. 111, 064502, 2013) wskazują na eksponencjalne skalowanie funkcji rozkładu wartości prędkości w układzie upakowanych kul. Bliższe spojrzenie na te dane pokazuje jednak coś innego. Przeanalizowaliśmy ten problem używając narzędzi numerycznych i modelu o zmiennej porowatości. Zbadaliśmy m.in. obszar niskich i wysokich porowatości (układy rozrzedzone), gdzie pokazaliśmy, że funkcje rozkładu odpowiadają rozkładom Gaussa. Zaproponowaliśmy prostą interpretację na gruncie centralnego twierdzenia granicznego.

Biuro Projektów Zagranicznych UWr

Spotkanie informacyjne dotyczące programu Horyzont 2020

Przedstawione zostaną możliwości aplikowania zarówno w ramach grantów indywidualnych, jak i projektów realizowanych w konsorcjach.

dr Janusz Szwabiński

Dyfuzja innowacji na sieciach małego świata

Prof. David Blaschke, IFT, University of Wroclaw

Introduction to Heavy ​Ion Collisions and Matter under Extreme Conditions VIII

This is the eighth seminar/lecture talk performed within the monographic lecture course run by D. Blaschke, K. Redlich, and L.Turko. The course is devoted to master students, PhD students and all interested in the subject. More details in: http://panoramix.ift.uni.wroc.pl/pluginfile.php/10955/mod_resource/content/2/Monografic_Lecture_HIC 2015.pdf

mgr Tomasz Golan

Modelowanie efektów jądrowych w generatorze oddziaływań neutrin NuWro Modeling nuclear effects in NuWro neutrino event generator

Neutrina są neutralnymi cząstkami o znikomej masie, które niezwykle słabo oddziałują z materią. Ich detekcja jest możliwa, lecz wyjątkowo trudna - obserwuje się cząstki, które powstały w wyniku oddziaływań neutrin. Każdy pomiar bezpośrednio zależy od modeli teoretycznych użytych w analizie danych. Pomostem między teorią a pomiarem są generatory Monte Carlo. Umożliwiają one interpretację tego co się widzi w detektorze. Na seminarium przestawię generator oddziaływań neutrin NuWro. Skoncentruję się na modelu propagacji cząstek z pierwotnego wierzchołka przez jądro atomowe, który opisywany jest w ramach kaskady wewnątrzjądrowej. Jako przykład zastosowania NuWro zaprezentuję analizę danych eksperymentu MiniBooNE. Neutrino is an electrically neutral, almost massless and extremely weakly interacting elementary particle. Its detection is possible but very difficult. It is based on the observation of particles created in neutrino interactions. Thus, every measurement depends directly on theoretical models used in a data analysis. Monte Carlo generators are the bridge between theory and a measurement. They allow the interpretation of what one sees in a detector. The NuWro neutrino event generator will be presented at the seminar. I will focus on a particle propagation through nuclear matter (final state interactions), described in terms of intra-nuclear cascade. The analysis of the MiniBooNE data done using NuWro will be presented as an example of a possible usage of the generator.

Guests: Julia Diakiv and Vasyl Vasyuta

On our PhD seminar we will have two guests from the Lviv University, Ukraine. They will give 30 min talks each:

Julia Diakiv "Differential cross-section of photoeffect in space with minimal length" Vasyl Vasyuta "Quantum systems in space with spin noncommutativity of coordinate"

Dariusz Prorok

Statistical model in the description of particle production in heavy-ion collisions (Uwaga zmiana godziny!)

During an ultrarelativistic central heavy-ion collision the number of produced particles counts in thousands. The matter created at the first stage of such collision reaches extreme values of the density in the volume of the order of the size of a nucleus. This explains the abundance of finally measured particles. To describe the production quantitatively the matter is considered as a statistical system with two independent parameters: the temperature and the baryon number chemical potential. To model the evolution of the matter relativistic hydrodynamics is applied. As an example of this approach, the gold to gold collisions at Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory will be analysed successfully.

Dr hab. Daniel Bemmerer (Helmholtzzentrum Dresden-Rossendorf)

Underground nuclear astrophysics laboratories for the Sun, and for the Big Bang

After the resolution of the solar neutrino problem in 2002, the study of the Sun has now entered a precision era, and an entirely new dilemma has come up: New elemental abundance data from Fraunhofer line analyses are in contradiction with helioseismological observables. Observations of 13N and 15O neutrinos from the Sun may address this so-called solar abundance problem, but their interpretation will require precise nuclear reaction data. Due to the low cross sections involved, such data can only be provided by experiments in an underground low-background setting. Work at the world's only underground accelerator, the 0.4 MV LUNA machine in Gran Sasso (Italy), on solar fusion reactions and on the Big Bang production of lithium-6 and -7 will be reviewed. Higher-energy underground accelerators are planned in Italy and also at the Dresden Felsenkeller in Germany.

Michal Naskret

What is happening at CERN?

This is HoMPA seminar (prof. Kucharczyk/Dr. Klaehn) talk invited to be presented within Theory of Elementary Particles Division seminar. NB - no obligatory ties! We have all heard about the Large Hadron Collider experiment at CERN, but do we actually know what is happening there? Why is it important? Why there are two similar experiments at the Brookhaven National Laboratory and at the Joint Institute for Nuclear Research in Dubna? What happens when heavy ions collide? How can we describe heavy ion collisions[1]? What is the quark-gluon plasma and why is it important[2]? What is the hadron resonance gas model[3]? Why is the freeze-out interesting[4]? In my talk I will address all of those questions. I will also present my research topics [5] in the heavy ion collisions universe. References [1] J.I.Kapusta: "Finite- temperature field theory", CUP (1989). [2] K.Yagi, T.Hatsuda and Y.Miaki: "Quark-Gluon Plasma", CUP (2005). [3] J. Jankowski and D. Blaschke: "Chiral condensate in hadronic matter", PRD 87 (2013) 105018. [4] D. Blaschke, J. Berdermann, J. Cleymans and K. Redlich: "Chiral condensate and Mott-Anderson freeze-out", Few Body Syst. 53 (2012) 99. [5] D. Blaschke and M. Naskret, "Mott-Anderson freeze-out and the strange matter horn", in preparation (2014).

Jakub Żmuda

Konstruowanie efektywnych generatorów oddziaływań neutrin

Seminarium dotyczyć będzie konstrukcji generatorów Monte Carlo oddziaływań neutrin dla neutrinowych eksperymentów oscylacyjnych. Poruszone zostaną m.in. problemy efektywnego sposobu losowania zmiennych z rozkładów prawdopodobieństwa, wyborze układu odniesienia dla obliczeń a także generowania prawdopodobieństw na podstawie modeli fizycznych.

Kajetan Niewczas

O rekonstrukcji oddziaływań neutrin na skorelowanych nukleonach na podstawie danych z eksperymentu ArgoNeuT oraz symulacji NuWro

Podczas seminarium zostanie omówiona publikacja ArgoNeuT Collaboration dotycząca wykrywania przeciwnie skierowanych par proton-proton powstałych w wyniku rozpraszania neutrin na tarczy argonowej. W pracy zaproponowano odważną tezę dotyczącą rekonstrukcji oddziaływań na skorelowanych parach neutron-proton. Podana formuła oraz dane eksperymentalne zostaną skonfrontowane z wynikami symulacji NuWro.

Prof. Christian Spiering (DESY Zeuthen)

High energy neutrino astronomy - a glimpse to the promised land

First ideas to build a large underwater neutrino detector started in 1973. After a fourty-year march we now are close to the promised land: IceCube, the cubic kilometer neutrino telescope at the South Pole reports high-energy neutrino events which apparently cannot be explained by interactions of neutrinos generated in the Earth's atmosphere. These observations are opening a third window to the high-energy universe (after charged cosmic rays and gamma rays). The talk gives a short introduction into history, physics goals and functional principles of neutrino telescopes and then focuses to the results obtained during the last 2 years by IceCube. A discussion of future perspectives of the field will conclude the talk.

prof. dr hab. Mariusz P. Dąbrowski (IF US)

Weak singularities in Friedmann cosmology and varying physical constants

I will present a variety of non-standard (non-big-bang/big-crunch) cosmological singularities such as big-rips, sudden future singularities, finite scale factor singularities, big-separations, w-singularities (or type II-V), their variants and generalizations. I will show that most of them are of a weak type and are not characterized by geodesic incompletness. Besides, some of them may fit observational data (supernovae, baryon acoustic oscillations, CMB, redshift drift) and so serve as the dark energy. I will also discuss the influence of the possible variation of the fundamental physical constants such as the gravitational constant G and the velocity of light c onto the nature of these singularities.

Jacek Stefan

Wpływ cech fizyko-metrycznych i stanu klinicznego hospitalizowanych przyjętych w celu inwazyjnej diagnostyki terapii choroby wieńcowej na dawkę promieniowania rentgenowskiego w trakcie procedury

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Cezary Juszczak

Electron interactions in NuWro (zmiana terminu!)

NuWro is neutrino nucleus interactions simulation software developed by Wroclaw neutrino group. Currently and affort is being made to incorporate also electron nucleus interactions. The first electron results will be presented and the plans discussed.

dr Maciej Matyka + laureaci konkursu

Ogłoszenie zwycięzców i prezentacje laureatów tegorocznego konkursu Fizbit

W ramach seminarium ogłoszone zostaną wyniki tegorocznej edycji konkursu na oprogramowanie popularyzujące fizykę. Przedstawione zostaną krótko prace zgłoszone w tym roku i rozdane będą nagrody. W drugiej części laureaci (3 pierwsze miejsca) zaprezentują swoje prace.

dr hab. Rafał Demkowicz-Dobrzański (IFT UW)

Metrologia Kwantowa

Detektory fal grawitacyjnych czy zegary atomowe są jednymi z najbardziej precyzyjnych urządzeń pomiarowych skonstruowanych przez człowieka. Wykorzystywane w typowych eksperymentach klasyczne stany światła oraz nieskorelowane grupy atomów powowodują, że precyzja pomiarów jest ograniczona przez tak zwany szum śrutowy związany z niezależnym i probabilistycznym zachowaniem każdego z fotonów/atomów w eksperymencie interferometrycznym. Metrologia kwantowa proponuje wykorzystanie splątania kwantowego jako metody do obejścia ograniczeń wynikających z obecności szumu śrutowego i dalszej poprawy precyzji w eksperymentach interferometrycznych. Podczas seminarium omówię ostatnie osiągnięcia z dziedziny metrologii kwantowej i pokażę fundamentalne ograniczenia jakie na możliwości wykorzystania splątania kwantowego do poprawy precyzji nakłada obecność dekoherencji.

Prof. David Blaschke

Towards a unified EoS for quark-hadron matter

A main problem to arrive at a unified EoS for quark-hadron matter is the description of the mass spectrum of hadrons as being strongly corrrelated multiquark states (cluster decomposition) and their in-medium modification including their dissociation due to the Mott effect. The formulation can be achieved in the form of a generalized Beth-Uhlenbeck EoS with medium dependent phase shifts describing the multiquark correlations. A generic ansatz, motivated by calculations within the PNJL model is introduced and first results are presented.

Krzysztof Graczyk

Selected Examples of Computational Activity of Wrocław Neutrino Group

I will present the selected list of problems investigated by some members of the neutrino group during last year. The attention will be concentrated on the presentation of the computational methods, which have been applied. Students are welcome to participate.

dr Paweł Gusin

D2-brana jako tunel czasoprzestrzenny (wormhole) i liczba wszechświatów

Przedstawię klasę rozwiązań teorii typu IIA z D2-braną. Rozwiązania te mogą być interpretowane jako tunele czasoprzestrzenne w 4-wymiarach. Również przedstawię spekulacje związane z istnieniem tuneli czasoprzestrzennych i możliwą liczbę wszechświatów wynikającą z obserwowanej wartości stałej kosmologicznej.

dr hab. Leszek Hadasz (IF UJ)

Coset conformal field theories and super-Liouville -- double-Liouville equivalence

During the seminar I will concentrate on three topics: - the construction of coset 2-dim conformal field theories; - the super-Liouville -- double-Liouville equivalence motivated by the coset description of some 2-dim CFT models and by the AGT relation; - the role played by coset CFT models in the AdS3/CFT2 correspondence.

dr Katarzyna Roszak (Politechnika Wr)

Zależność zaniku splątania kubitów spinowych w kropkach kwantowych od pola magnetycznego

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Dariusz Prorok

Semi-rigorous statistical inference: fitting multiplicities in Au-Au collisions at sqrt{s_{NN}} = 62.4 and 200 GeV

In the first introductory part I will explain what the value of the so-called chi-squared function at the minimum means really. Additionally, I will give reasons why the commonly accepted condition for "a good fit" is that this value should be roughly equal to the number of degrees of freedom. Then I will show that carefree application of this criterion could lead to confused inference. To this end the detailed analysis of the fits to charged particle multiplicity distributions measured by the PHENIX Collaboration in Au-Au collisions at sqrt{s_{NN}}=62.4 and 200 GeV will be presented.

dr hab. Franco Ferrari (IF Uniwersytet Szczeciński)

The physics of polymer knots and links: Some analytic and numerical aspects

The physics of polymer knots and links is a multidisciplinary subject. On one side, it is a playground for field theoretical techniques, like the renormalization group method and, more recently, for topological field theories. On the other side, the investigations of the statistical mechanics of polymer rings have also a feedback in field theories. Examples are a few progresses in treating field theories with constraints and a class of identities that allow to simplify complicated interactions in scalar field theories. Moreover, models of polymer knots and links have a range of applications that go beyond the physics of polymers and become relevant to other disciplines, in which the topological properties of quasi one-dimensional objects play an important role. This is the case of magnetohydrodynamics and of some systems of quasiparticles with non-trivial statistics in solid state physics. Nowadays, the behavior of single polymer knots can be checked experimentally and it is possible to create polymer melts containing a very high percentage of polymer rings entangled together. Properties which are too difficult to be studied directly via experiments may be investigated thanks to reliable numerical simulations. In this introductory talk some of the recent experimental, analytical and numerical results in the physics of polymer knots and links will be presented.

dr hab. Zbigniew Koza

Parallelism beyond MPI: A Great Challenge of Computational Physics

I will show how the recent developments in the computer hardware open new perspectives in the algorithmic aspects of computational physics.

mgr Łukasz Juchnowski

The dynamical Schwinger effect in the electron-positron plasma

We study the dynamical Schwinger effect in the vacuum excitation of the electron-positron plasma under action of a "laser pulse" of the simplest configuration: a linearly polarized,time-dependent and spatially homogeneous electric field. Methodical basis of this investigation is the kinetic equation which is an exact consequence of the basic equations of motion of QED in the considered field model. In the present work we investigate some features of the residual electron-positron plasma and the transient process of its formation. Moreover we compare predictions on the basis of different WKB-type approximations with our results. Such a comparison demonstrates a considerable divergence. results in strong non-stationary fields.

Aleksandr Dubinin

Mott-hadron resonance gas

We present an effective model for the generic behaviour of hadron masses and phase shifts at finite temperature which shares basic features with recent developments within the PNJL model for correlations in quark matter. On this basis we obtain the transition between a hadron resonance gas phase and the quark gluon plasma in the spirit of the generalized Beth-Uhlenbeck approach where the Mott dissociation of hadrons is encoded in the hadronic phase shifts.

prof. P. Machnikowski (Politechnika Wr)

Pomiar stanów spinowych w podwójnej kropce kwantowej poprzez statystykę szumu styku punktowego

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Prof. dr hab. Dariusz Kaczorowski (INTiBS PAN)

Nadprzewodnictwo ciężkofermionowe i kwantowe zjawiska krytyczne w układach f-elektronowych

W wykładzie omówione zostaną podstawowe pojęcia fizyki układów z silnie skorelowanymi elektronami, ze szczególnym uwzględnieniem charakterystyk ciężkofermionowych, kwantowych zjawisk krytycznych i niekonwencjonalnego nadprzewodnictwa. Krótki, historyczny przegląd odkryć dokonanych w obszarze nadprzewodnictwa ciężkofermionowego stanie się przyczynkiem dla prezentacji kilku wyników naszego zespołu badawczego w INTiBS PAN, uzyskanych na przestrzeni ostatnich kilku lat. W podsumowaniu, podjęta zostanie próba sformułowania najbardziej intrygujących otwartych problemów, związanych z omawianymi zagadnieniami.

Michal Sokolowski

Finding the Hybrid Equation of State

After a brief introduction to compact stars a simple class of hybrid equation of state (EoS) with three parameters is investigated concerning the mass-radius relationships of compact stars that will be predicted from it by solving the Tolman-Oppenheimer-Volkoff equations. First results of the Master Thesis project are presented and an outlook is given on how to find the most likely hybrid EoS by a Bayesian analysis of the results using available and future pulsar observations.

Jarek Gołembiewski

Funkcja rozkładu prędkości w przepływach przez ośrodki porowate

Seminarium poświęcone będzie zagadnieniu badania funkcji rozkładu prędkości cieczy przepływającej przez ośrodek porowaty. Opierając się na pracy S. Sujita i innych (PRL 111, 064501 (2013)) oraz własnych badaniach, przedstawię zarówno doświadczalne, jak i numeryczne podejście do tego problemu.

Krzysztof Graczyk

Computational Activity of Wrocław Neutrino Group

I will review the scientific activity of our neutrino group. The attention will be concentrated on the computational activity, methods and results. Students are welcome to participate.

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USOS - szkolenie

dr hab. Grzegorz Kondrat

Porowatość (w) perkolacji

Opowiem o pewnym ciekawym problemie na styku perkolacji i modelowania ośrodków porowatych

Michał Szcześniak

Badania układu Ho/Mo(112) metodami ab initio.

Podczas seminarium opowiem o moich badaniach, wplatając te informacje w zwięzły wykład, dotyczący obliczeń metodami ab initio.