Data: 13.10.2023
Miejsce: Sala 422 12:00
Temat: Galactic Chemical Evolution of rapid neutron capture elements and with short lived radioisotopes
Osoba: Benjamin Wehmeyer (IFT)
Opis: 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 (subclasses) of supernovae. R-process elements have been measured in a large fraction of metal-poor stars. Galactic archeology studies show that the r-processabundances among thesestars 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 pointto 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 fot 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.

Data: 03.02.2023
Miejsce: Sala 422 12:15
Temat: Adaptive meshfree approach to solving partial differential equations
Osoba: Gregor Kosec (Jožef Stefan Institute Ljubljana)
Opis: 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

Data: 27.01.2023
Miejsce: Sala 422 12:15
Temat: New results on the structure and integral parameters of compact stars
Osoba: Armen Sedrakian
Opis: I will discuss the construction of a set of hyperonic equations of state (EoS) by assuming SU(3) symmetry within the baryon octet and by using a covariant density functional (CDF) theory approach. The low-density regions of our EoS are constrained by terrestrial experiments, while the high-density regime is modeled by systematically varying the nuclear matter skewness coefficient and the symmetry energy slope. The sensitivity of the EoS predictions is explored in terms of z-parameter of the SU(3) symmetric model that modifies the meson-hyperon coupling constants away from their SU(6) symmetric values. Our results show that model EoS based on our approach can support static Tolman- Oppenheimer-Volkoff (TOV) masses in the range 2.3-2.5M⊙ in the large-skewness and small-z regime, however, such stars contain only a trace amount of hyperons compared to SU(6) models. I will also discuss the consequences of phase transition in dense QCD on the properties of compact stars and implications for the observational program in gravitational wave and X-ray astrophysics. The key underlying assumption of our modeling is a strong first-order phase transition past the point where the hadronic branch of compact stars reaches the two-solar mass limit. Our analysis predicts ultra-compact stars with very small radii – in the range of 6-9 km – living on compact star sequences that are entirely consistent with the current multi-messenger data. We show that sequences featuring two-solar mass hadronic stars consistent with radio-pulsar observations can account naturally for the inferences of large radii for massive neutron stars by NICER X-ray observations of neutron stars and the small radii predicted by gravitational waves analysis of the binary neutron star inspiral event GW170817 if a strong QCD phase transition takes place.

Data: 20.01.2023
Miejsce: Sala 422 12:15
Temat: Strange white dwarfs
Osoba: Alessandro Drago (INFN and University Ferrara)
Opis: 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

Data: 13.01.2023
Miejsce: Sala 422 12:15
Temat: Physics-informed neural network models for predicting the electronic structure of matter
Osoba: Attila Cangi (CASUS/HZDR)
Opis: 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).

Data: 16.12.2022
Miejsce: Sala 422 12:15
Temat: Multi-quark clusters and their Mott dissociation in hot, dense matter
Osoba: Mateusz Cierniak
Opis: 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.

Data: 09.12.2022
Miejsce: Sala 422 12:15
Temat: Neutrinos in Heaven and on Earth: from Baryogenesis to Monte Carlo Generation
Osoba: Dmitry Zhuridov
Opis: 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.

Data: 02.12.2022
Miejsce: Sala 60 12:15
Temat: Path to accurate neutrino cross sections
Osoba: Artur Ankowski
Opis: 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.

Data: 25.11.2022
Miejsce: Sala 422 12:15
Temat: Investigation of exotic particle spectrum in cold compact stars
Osoba: Vivek Thapa (Indian Institute of Technology Jodhpur)
Opis: 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.

Data: 18.11.2022
Miejsce: Sala 422 12:15
Temat: Who put a knot in my 3d N = 2 supersymmetric gauge theory?
Osoba: Hélder Larraguível (Uniwersytet Warszawski)
Opis: 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.

Data: 04.11.2022
Miejsce: Sala 60 12:15
Temat: 2022 Nobel Prize in Physics for Quantum Information Experiments
Osoba: Artur Barasiński
Opis: 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.

Data: 28.10.2022
Miejsce: Sala 60 12:15 
Temat: A new WPI research center at Hiroshima University – prospects and missions
Osoba: Chihiro Sasaki
Opis: 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.

Data: 21.10.2022
Miejsce: Sala 422 12:15
Temat: Dynamical and transport properties of deconfined matter in hot QCD
Osoba: Valeriya Mykhaylova
Opis: 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)

Data: 07.10.2022
Miejsce: Sala 60 12:15
Temat: The German Centre of Astrophysics in Görlitz
Osoba: David Blaschke (IFT)
Opis: 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

Data: 10.06.2022
Miejsce: Sala 422 12:15
Temat: Multicomponent relativistic dissipative fluid dynamics from the Boltzmann equation
Osoba: Etele Molnar (ISE SSF, WFA UWr)
Opis: 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.

Data: 02.06.2022
Miejsce: Sala 422 16:00
Temat: State reduction, gravity, and twistor theory
Osoba: Prof. Maciej Dunajski, Cambridge University
Opis: 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

Data: 02.06.2022
Miejsce: Sala 422 14:15
Temat: Four facets of geometry
Osoba: Prof. Maciej Dunajski (University of Cambridge)
Opis: 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.

Data: 13.05.2022
Miejsce: Sala 60 12:15
Temat: Nuclear astrophysics at the Felsenkeller underground laboratory in Dresden
Osoba: Daniel Bemmerer (Dresden)
Opis: 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.

Data: 29.04.2022
Miejsce: Sala 422 12:00
Temat: Measuring the speed of sound in matter created in heavy-ion collisions
Osoba: Agnieszka Sorensen (Seattle)
Opis: 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.

Data: 22.04.2022
Miejsce: Sala 422 12:00
Temat: How Strings May Heal the Fabric of Cosmos
Osoba: Falk Hassler (IFT)
Opis: 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.

Data: 12.04.2022
Miejsce: Sala 60 13:00
Temat: Quantum Dynamics far from Equilibrium
Osoba: prof. Matthias Kaminski (University of Alabama, USA)
Opis: 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.

Data: 01.04.2022
Miejsce: Sala 60 12:15
Temat: Special Relativity and Strong Fields: A personal perspective
Osoba: Johann Rafelski, Department of Physics, The University of Arizona
Opis: 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.

Data: 25.03.2022
Miejsce: Sala 422 12:15
Temat: Thermalization, evolution and observables in integrated hydrokinetic model of A+A collisions
Osoba: Yuri Sinyukov, Bogolyubov Institute, Kiev & ITP University of Wroclaw
Opis: 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.

Data: 04.02.2022
Miejsce: Sala zoom 12:15
Temat: Modeling neutrino-nucleus cross sections for accelerator-based experiments
Osoba: Natalie Jachowicz (Ghent)
Opis: 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

Data: 14.01.2022
Miejsce: Sala Rzew. 12:15
Temat: 2021 Nobel Prize in Physics for Complexity
Osoba: Prof. Maciej Nowak (Jagiellonian University, Kraków)
Opis: 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.

Data: 17.12.2021
Miejsce: Sala Rzewu 12:15
Temat: Hundred Years of Relativity Theory in Poland
Osoba: Prof. Richard Kermer (Sorbonne Paris)
Opis: 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.

Data: 03.12.2021
Miejsce: Sala DSF 12:15
Temat: Identification and quantification of nonclassicality of experimental optical fields
Osoba: Jan Perina (Palacky University, Olomouc, Czech Republic)
Opis: 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.

Data: 26.11.2021
Miejsce: Sala DSF 12:15
Temat: The egg of excellence: modeling of heavy-ion collisions
Osoba: Dr Pasi Huovinen
Opis: 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.

Data: 19.11.2021
Miejsce: Sala DSF 12:15
Temat: Multi-Messenger Signals from Non-Rotating and Rapidly Rotating Stellar Core Collapse
Osoba: Dr. Shota Shibagaki (Fukuoka, Japan)
Opis: 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.

Data: 05.11.2021
Miejsce: Sala DSF 12:15
Temat: The Physics of Inhomogeneous Warm Dense Matter
Osoba: dr Zhandos Moldabekov (CASUS, Görlitz)
Opis: 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)

Data: 29.10.2021
Miejsce: Sala DSF 12:15
Temat: Relativistic density functional approach to a unified description of quark-hadron matter
Osoba: Dr Oleksii Ivanytskyi
Opis: 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.

Data: 11.06.2021
Miejsce: Sala I-net 12:00
Temat: Short-range correlations in nuclear systems
Osoba: Eliazer Piasetzky (Tel Aviv)
Opis: 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.

Data: 28.05.2021
Miejsce: Sala I-net 12:00
Temat: Revisiting the Polyakov Loop Nambu-Jona-Lasinio model at finite baryonic density
Osoba: Oleksii Ivanytskyi (IFT)
Opis: 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.

Data: 21.05.2021
Miejsce: Sala I-net 12:00
Temat: Gravitational waves from the next galactic core-collapse supernova
Osoba: Marek Szczepańczyk (Florida)
Opis: 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.

Data: 14.05.2021
Miejsce: Sala I-net 12:00
Temat: Hydrodynamic attractors in heavy ion collisions
Osoba: Jakub Jankowski (IFT)
Opis: 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

Data: 07.05.2021
Miejsce: Sala I-net 12:00
Temat: Universal relation for neutron stars with heavy baryons at finite temperature
Osoba: Armen Sedrakian (IFT)
Opis: 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.

Data: 30.04.2021
Miejsce: Sala I-net 12:0
Temat: Multiscale financial correlations in Ising-inspired agent-based models
Osoba: Rafał Kowalski (INP PAN)
Opis: 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.

Data: 23.04.2021
Miejsce: Sala I-net 12:00
Temat: Decoherence and noise in an environment of photons and gravitons
Osoba: Zbigniew Haba
Opis: 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.

Data: 16.04.2021
Miejsce: Sala I-net 12:00
Temat: Exploring the QCD phase diagram: Approaching the phase transition from the hadronic side
Osoba: Hannah Elfner (FIAS Frankfurt)
Opis: 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.

Data: 09.04.2021
Miejsce: Sala I-net 12:00
Temat: Galactic Chemical Evolution of r-process elements
Osoba: Benjamin Wehmeyer (Research Centre for Astronomy and Earth Sciences, Budapest)
Opis: 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.

Data: 26.03.2021
Miejsce: Sala I-net 12:00
Temat: Towards ab-initio computations of neutrino scattering on medium-mass nuclei
Osoba: Joanna Sobczyk (Universität Mainz)
Opis: 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.

Data: 19.03.2021
Miejsce: Sala I-net 12:00
Temat: Dark forces from right-handed neutrinos
Osoba: Xun-Jie Xu (Université Libre Bruxelles, Brussels, Belgium)
Opis: 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

Data: 12.03.2021
Miejsce: Sala Inter 12:00
Temat: Gravitational waves from ultra-compact stars
Osoba: Marek Abramowicz (CAMK Warsaw)
Opis: 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.

Data: 29.01.2021
Miejsce: Sala I-net 12:00
Temat: GR: Quantum spacetime symmetries: between theory and phenomenology of quantum gravity
TP: Cosmological perturbations and black hole singularities in loop quantization
Osoba: Giacomo Rosati, Tomasz Pawłowski
Opis:
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”.

Data: 22.01.2021
Miejsce: Sala I-net 12:00
Temat: Charged hadron production in central Ar+Sc collisions at the CERN SPS
Osoba: Maciej Lewicki
Opis: PhD Thesis defense

Data: 15.01.2021
Miejsce: Sala I-net 12:00
Temat: Neutrino Physics Division – research activity
Osoba: Jan Sobczyk
Opis: I will give an overview of the research activity in the Neutrino Physics Division.

Data: 08.01.2021
Miejsce: Sala I-net 12:00
Temat: Matter under Extreme Conditions
Osoba: Krzysztof Redlich & David Blaschke
Opis: 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.

Data: 18.12.2020
Miejsce: Sala team 12:00
Temat: Quantum correlations – from C* algebra and dynamics of open systems towards experimental applications in quantum optics.
Osoba: prof. Marek Mozrzymas, UWr
Opis: 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.

Data: 11.12.2020
Miejsce: Sala team 12:00
Temat: Towards quantum gravity
Osoba: prof. dr hab. Jerzy Kowalski-Glikman, UWr
Opis: 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.

Data: 27.11.2020
Miejsce: Sala team 12:00
Temat: Division of Applied Computer Science & Statistical Physics
Osoba: prof dr hab. Zbigniew Koza, IFT UWr
Opis: 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.

Data: 27.11.2020
Miejsce: Sala team 12:00
Temat: Statistical physics of strongly correlated systems
Osoba: dr hab. Armen Sedrakian, prof. UWr, IFT UWr
Opis: 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.

Data: 20.11.2020
Miejsce: Sala team 12:00
Temat: Supermassive black hole in the centre of our Galaxy – 2020 Nobel prize in physics
Osoba: Prof. Andrzej Pigulski, IA UWr
Opis: 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.

Data: 13.11.2020
Miejsce: Sala Zoom 12:00
Temat: From Data to Understanding – The Center for Advanced Systems Understanding
Osoba: Dr Michael Bussmann, CASUS Görlitz & Helmholtz Zentrum Dresden-Rossendorf
Opis: 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

Data: 19.06.2020
Miejsce: Sala team 12:15
Temat: Polarization effects in neutrino-nucleon interactions
Osoba: mgr Beata Kowal, IFT UWr
Opis: 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.

Data: 12.06.2020
Miejsce: Sala team 12:15
Temat: Neutrino-Electron Scattering in NuWro
Osoba: dr Dmitry Zhuridov, IFT UWr
Opis: 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.

Data: 29.05.2020
Miejsce: Sala team 12:15
Temat: The future is quantum – IBM Q experience
Osoba: dr Piotr Biskupski, IBM Polska s.a.
Opis: 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 .

Data: 22.05.2020
Miejsce: Sala team 12:15
Temat: the seminar is canceled
Osoba: Election Meeting
Opis: –

Data: 15.05.2020
Miejsce: Sala team 12:15
Temat: Physical cosmology by James Peebles
Osoba: prof. Jan Ostrowski, ENS Lyon
Opis: 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’.

Data: 08.05.2020
Miejsce: Sala team 12:15
Temat: Testing quantum spacetime with gamma-ray-burst neutrinos and photons
Osoba: dr Giacomo Rosati, IFT UWr
Opis: 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.

Data: 24.04.2020
Miejsce: Sala net 12:15
Temat: Neutron star mergers: Equation of state and dissipative hydrodynamics.
Osoba: prof. Armen Sedrakjan, IFT UWr
Opis: 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.

Data: 27.03.2020
Miejsce: Sala T-K 12:15
Temat: Epidemics modeling. What can we infer from the statistics?
Osoba: dr hab. Grzegorz Kondrat, IFT UWr
Opis: 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.

Data: 31.01.2020
Miejsce: Sala 60 12:15
Temat: New International System of Units
Osoba: prof. Anna Szmyrka-Grzebyk, INTiBS PAN, Wrocław
Opis: 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.

Data: 24.01.2020
Miejsce: Sala 422 12:15
Temat: Detectability of Macroscopic Structures in Directed Networks
Osoba: dr Mateusz Wiliński, UW
Opis: 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.

Data: 17.01.2020
Miejsce: Sala 60 12:1
Temat: All details will be sent
Osoba: Election Meeting
Opis: All details: the place and time will be given and confiremed by the authoriesed person

Data: 10.01.2020
Miejsce: Sala 422 12:15
Temat: Physical mathematics, string theory, and knots-quivers correspondence
Osoba: prof. Piotr Sułkowski, UW
Opis: 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.

Data: 13.12.2019
Miejsce: Sala 60 12:15
Temat: New perspectives on our place in the universe
Osoba: dr hab. Joanna Molenda-Żakowicz, IA UWr
Opis: 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.

Data: 06.12.2019
Miejsce: Sala 422 12:15
Temat: Quantum kinetic approach to particle production in time dependent external field
Osoba: mgr Łukasz Juchnowski, IFT UWr
Opis: the public defence of the doctoral thesis

Data: 29.11.2019
Miejsce: Sala 422 12:15
Temat: Why and how should we test (theory of) gravity on cosmological scales
Osoba: dr hab. Wojciech Hellwing, CFT PAN
Opis: 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!

Data: 22.11.2019
Miejsce: Sala 422 12:15
Temat: The handful of new insights regarding algebra enlargements and spacetime with a gravitational analog of the magnetic monopole
Osoba: dr Remigiusz Durka, IFT UWr
Opis: 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).

Data: 08.11.2019
Miejsce: Sala 60 12:15
Temat: New International System of Units
Osoba: prof. Anna Szmyrka-Grzebyk, INTiBS PAN, Wrocław
Opis: 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.

Data: 25.10.2019
Miejsce: Sala 422 12:15
Temat: Fractals and Agents in Economics: the case of Bitcoin
Osoba: dr hab. Paweł Oświęcimka, IFJ PAN Kraków
Opis: 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.

Data: 18.10.2019
Miejsce: Sala 422 12:15
Temat: Quantum and classical Virasoro conformal blocks: advances in the theory, and new applications
Osoba: dr Marcin Piątek, Univ. of Szczecin
Opis: 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.

Data: 11.10.2019
Miejsce: Sala 422 12:15
Temat: Topological Quantum Sensors?
Osoba: dr Thomas Bahder, ARO Tokyo
Opis: 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.

Data: 11.10.2019
Miejsce: Sala 412 14:30
Temat: Army Research Office (ARO) Overview and Physics Division Objectives
Osoba: dr Thomas Bahder, ARO Tokyo
Opis: 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.

Data: 04.10.2019
Miejsce: Sala 422 12:15
Temat: How to use low-mass stars to test theories of gravity
Osoba: dr Aneta Wojnar, Federal University of Espirito Santo, Vitoria
Opis: 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.

Data: 28.06.2019
Miejsce: Sala 422 12:15
Temat: Effective-Model Perspective on QCD Phenomenology – obrona pracy doktorskiej
Osoba: Michał Marczenko
Opis: 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.

Data: 14.06.2019
Miejsce: Sala 422 12:15
Temat: publiczna obrona rozprawy doktorskiej
Osoba: Dipl.-Phys. Niels-Uwe Bastian, IFT UWr
Opis: tytuł rozprawy doktorskiej: Density functional theory for a unified description of quark-hadron matter and applications in heavy-ion collisions and astrophysics

Data: 14.06.2019
Miejsce: Sala 60 11:00
Temat: Dissolution at the pore scale: comparing simulations and experiments
Osoba: prof. Anthony Ladd, University of Florida
Opis: 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.

Data: 07.06.2019
Miejsce: Sala 60 12:15
Temat: Novel critical behaviour: the statistical mechanics of bird swarms
Osoba: prof. Helmut Satz, Univ. Bielefeld
Opis: 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.

Data: 24.05.2019
Miejsce: Sala 422 12:15
Temat: Exploring phases of dense matter with astrophysics of compact stars
Osoba: prof. dr hab. Armen Sedrakian, IFT UWr
Opis: 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.

Data: 17.05.2019
Miejsce: Sala 422 12:15
Temat: Phenomenology of the QCD phase transition
Osoba: Dipl.-Phys. Niels-Uwe Bastian, IFT UWr
Opis: 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.

Data: 10.05.2019
Miejsce: Sala 422 12:15
Temat: A fresh look at the gauge coupling unification and proton decay
Osoba: dr Kazuki Sakurai, UW
Opis: 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.

Data: 26.04.2019
Miejsce: Sala 422 12:15
Temat: Modeling Cold and Dense QCD Matter
Osoba: mgr Michał Marczenko, IFT UWr
Opis: 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.

Data: 12.04.2019
Miejsce: Sala 60 12:55
Temat: Decoding the QCD phase structure with relativistic nuclear collisions
Osoba: Prof. Peter Braun-⁠Munzinger ,GSI Darmstadt
Opis: 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.

Data: 12.04.2019
Miejsce: Sala 60 12:15
Temat: Charmonia as Probe of Deconfinement -⁠ Recent Results and Perspectives
Osoba: Prof. Johanna Stachel, Heidelber Univ.
Opis: 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.

Data: 29.03.2019
Miejsce: Sala 422 12:15
Temat: Percolation of k-mers on the square lattice
Osoba: prof. dr hab. Zbigniew Koza, IFT UWr
Opis: 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.

Data: 22.03.2019
Miejsce: Sala 422 12:15
Temat: An application of space-time spectral analysis for seismic-wave detection in Virgo interferometer
Osoba: dr Mateusz Denys, UW
Opis: 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.

Data: 15.03.2019
Miejsce: Sala 422 12:15
Temat: Fluid dynamics in porous media and beyond
Osoba: dr hab. Maciej Matyka, IFT
Opis: 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.

Data: 08.03.2019
Miejsce: Sala 422 12:15
Temat: New Approach to Colour Triplets of Quarks, Graded Extension of Lorentz Symmetries and Algebraic Confinement
Osoba: prof. dr hab. Jerzy Lukierski, IFT Uwr
Opis: 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)

Data: 22.02.2019
Miejsce: Sala 422 12:15
Temat: Ising model on (un-⁠)directed random graphs
Osoba: prof. dr hab. Adam Lipowski, UAM
Opis: 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.

Data: 11.01.2019
Miejsce: Sala 422 12:15
Temat: Scattering Theory Approach to the Thermodynamics of Hadrons
Osoba: dr Pok Man Lo, IFT UWr
Opis: 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.

Data: 04.01.2019
Miejsce: Sala 60 12:15
Temat: Optical tweezers. The Nobel Prize in Physics 2018
Osoba: dr Sławomir Drobczyński, PWr
Opis: 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.

Data: 14.12.2018
Miejsce: Sala 422 12:15
Temat: Probing fundamental physics with multi-messenger observations of neutron stars
Osoba: dr hab. Brynmore Haskell (CAMK Warsaw)
Opis: 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.

Data: 07.12.2018
Miejsce: Sala 422 12:15
Temat: The Statistical Mechanics of Particle Physics
Osoba: prof. Abhijit Bhattacharyya, University of Calcutta
Opis: 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.

Data: 23.11.2018
Miejsce: Sala 422 12:15
Temat: Role of multipartite entanglement in quantum teleportation
Osoba: dr Artur Barasiński, Palacky University
Opis: 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.

Data: 16.11.2018
Miejsce: Sala 422 12:15
Temat: Gravitation and accretion of matter.
Osoba: prof. dr hab. Edward Malec, UJ
Opis: 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.

Data: 26.10.2018
Miejsce: Sala 422 12:15
Temat: Loop Quantum Cosmology: from polymer quantization to Early Universe dynamics
Osoba: dr Tomasz Pawłowski, UW
Opis: 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.

Data: 12.10.2018
Miejsce: Sala 422 12:15
Temat: Spectrum Broadcast Structures And Quantum Origins Of Objectivity
Osoba: dr hab. Jarosław Korbicz, CFT PAN
Opis: 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.

Data: 05.10.2018 
Miejsce: Sala 422 12:15
Temat: Super hot and extremely dense – is there a critical point for the strong interaction?
Osoba: prof. dr Marlene Nahrgang, IMT Atlantique, Nantes
Opis: 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.

Data: 15.06.2018
Miejsce: Sala 422 12:15
Temat: The essence of gravity theory
Osoba: prof. dr hab. Jerzy Kijowski, CFT PAN
Opis: 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.

Data: 08.06.2018
Miejsce: Sala 422 12:15
Temat: On Relativistic Quantum Mechanics of the Majorana Particle
Osoba: prof. dr hab. Henryk Arodź, UJ
Opis: 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)

Data: 01.06.2018
Miejsce: Sala 60 12:15
Temat: Relativity vs quantum information
Osoba: dr hab. Andrzej Dragan, UW
Opis: 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.

Data: 25.05.2018
Miejsce: Sala 422 12:15
Temat: What can we learn from gravitational waves ?
Osoba: dr hab. Dorota Gondek-Rosińska, IA UZ
Opis: 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.

Data: 18.05.2018
Miejsce: Sala 422 12:15
Temat: Cellular automata approach to cardiac electrophysiology: a toy model or a generative proposition.
Osoba: prof. dr hab. Danuta Makowiec, IFTiA UG
Opis: 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.

Data: 18.05.2018
Miejsce: Sala 422 12:15
Temat: Cellular automata approach to cardiac electrophysiology: a toy model or a generative proposition.
Osoba: prof. dr hab. Danuta Makowiec, IFTiA UG
Opis: 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.

Data: 11.05.2018
Miejsce: Sala 422 12:15
Temat: Quantum entanglement from single particle information
Osoba: prof. dr hab. Adam Sawicki, CFT PAN
Opis: 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.

Data: 27.04.2018
Miejsce: Sala 422 12:15
Temat: Circuit-⁠QED: Microwave photonics with superconducting quantum circuits
Osoba: prof. dr hab. Adam Miranowicz, UAM
Opis: 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.

Data: 06.04.2018
Miejsce: Sala 422 12:15
Temat: Cellular automata approach to cardiac electrophysiology: a toy model or a generative proposition.
Osoba: prof. dr hab. Danuta Makowiec, IFTiA UG
Opis: 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.

Data: 29.03.2018
Miejsce: Sala 422 12:15
Temat: Binary neutron stars: Einstein’s richest laboratory
Osoba: prof. dr Luciano Rezzolla, Goethe University, Frankfurt (Main)
Opis: 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.

Data: 23.03.2018
Miejsce: Sala 422 12:15
Temat: Neutrino Properties Determined in Oscillation Experiments
Osoba: prof. dr hab. Ewa Rondio, NCNR.
Opis: 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.

Data: 16.03.2018
Miejsce: Sala 422 12:15
Temat: Online algorithms for physicists
Osoba: dr Paweł Laskoś-⁠Grabowski, IFT Uwr
Opis: 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.

Data: 09.03.2018
Miejsce: Sala 422 12:15
Temat: Gravitational wave astronomy – a new window on the Universe
Osoba: prof. dr hab. Andrzej Królak, IMP
Opis: 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.

Data: 02.03.2018
Miejsce: Sala 60 12:15
Temat: Computational Geology
Osoba: dr Marcin Dąbrowski, PIB Wrocław, UiO Oslo
Opis: 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.

Data: 26.01.2018
Miejsce: Sala DSF 12:15
Temat: Multiscale correlations in narrative texts
Osoba: prof. dr hab. Stanisław Drożdż, IFJ PAN
Opis: 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.

Data: 19.01.2018
Miejsce: Sala 422 12:15
Temat: Competing for perfection – Ultracold Fermi gases can be as perfect liquids as the superhot Quark-Gluon Plasma
Osoba: dr Marcus Bluhm, IFT UWr
Opis: 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.

Data: 12.01.2018
Miejsce: Sala 60 12:15
Temat: Seven terrestrial planets around the nearby ultra-cool dwarf star TRAPPIST-1
Osoba: dr Ewa Niemczura, IA UWr
Opis: 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.

Data: 05.01.2018
Miejsce: Sala 422 12:15
Temat: Machine Learning for MINERvA Physics Reconstruction
Osoba: dr Tomasz Golan, UWr
Opis: 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.