Seminář Ústavu teoretické fyziky

podzim 2023

Proběhlé semináře:

10. října 2023
Nucleosynthesis of Heavy Elements in Neutron-star Mergers and Rare Types of Supernovae
Prof. Dr. Daniel Siegel
Institute of Physics, University of Greifswald, Germany
(seminář v angličtině)

17. října 2023
Laboratory Astrophysics: Origin of Molecules in the Universe
doc. RNDr. Štěpán Roučka, Ph.D.
Department of Surface and Plasma Science, MFF Charles University
(seminář v angličtině)

24. října 2023
Infrared Phase of Thermal QCD
Ing. Ivan Horváth, Ph.D.
Nuclear Physics Institute, Czech Academy of Sciences
(seminář v angličtině)

I will discuss the rationale and evidence for the recently proposed phase of thermal QCD (IR phase) characterized by the decoupling and restored scale invariance of IR glue. Transition to this phase occurs at temperature 200 MeV < T < 250 MeV, well above the chiral crossover.

31. října 2023
Optimization of Eigenvalues for Differential Operators with Surface Interactions
Dr. Vladimir Lotoreichik, Ph.D., DSc.
Nuclear Physics Institute, Czech Academy of Sciences
(seminář v angličtině)

It is well known that among all domains of fixed volume the ball has the minimal area of the boundary. This geometric result has its counterparts in spectral theory. The most classical of them is the Faber-Krahn inequality, which states that among all domains of fixed volume the ball has the minimal ground-state eigenvalue of the Dirichlet Laplacian. In the last two decades the interest partially shifted towards optimization of the eigenvalues for differential operators with more involved boundary conditions, which describe physical systems with surface interactions. We will overview several recent results in this direction on (magnetic) Robin Laplacians and on Dirac operators with infinite mass boundary conditions.

7. listopadu 2023
Computational Approach to Neuroprosthesis: Inferring Functional Structure of the Brain from Its Spontaneous Activity
Karolína Korvasová, M.Sc., Ph.D.
Department of Software and Computer Science Education, MFF Charles University
(seminář v angličtině)

Being able to infer the functional structure of cortical neural networks from their spontaneous activity would advance our understanding of neural dynamics and have important applications in the field of visual prosthetics, as functional properties of neurons in the visual cortex cannot be measured directly in blind subjects. We designed a method that estimates the structure of the orientation preference map in the primary visual cortex. Using this method, we were able to show that functional, as well as spatial properties of the sites stimulated with a cortical visual prosthesis in blind humans determine the perceptual outcome. In this talk I will first introduce some basic concepts of neurobiology and discuss how biological neural networks can be modeled. Next, I will present a large-scale model of the primary visual cortex developed in the group of Ján Antolík (MFF UK) that was used to design the method that infers functional structure from spontaneous activity. Finally, I will present the results of this method applied to electrophysiological recordings from the visual cortex of sighted non-human primates and blind human volunteers.

14. listopadu 2023
Astrobiology: Life in Other Worlds
RNDr. Tomáš Petrásek, Ph.D.
Institute of Physiology, Czech Academy of Sciences
(seminář v angličtině)

The possibility of life elsewhere is one of the greatest questions, intriguing both scientists and laymen since ancient times. Although we have learned a lot since then, the answer to this question is still shrouded in mystery. It is also the focus of the science of astrobiology. Although commonly considered a science of extraterrestrial life, it would be better described as the study of life in the universe - including ourselves and our planet. Are we alone? The quest to find the answer - whatever it is - is also the quest to understand ourselves and our place in the universe.

21. listopadu 2023
Graph Coloring - Connections and Curiosities
prof. Mgr. Zdeněk Dvořák, Ph.D.
Computer Science Institute, MFF Charles University
(seminář v angličtině)

28. listopadu 2023
Terahertz Spin Currents in Magnetically Ordered Thin Films
RNDr. Lukáš Nádvorník, Ph.D.
Department of Chemical Physics and Optics, MFF Charles University
(seminář v angličtině)

Shortly after the recent discovery of the spintronic emission of pulses of terahertz (THz) radiation (Seifert et al. 2016), new prospects for a phase- and frequency-resolved detection of ultrashort spin currents have emerged. The analysis of emitted THz pulses has provided both fundamental and application-relevant insights into the generation, propagation and conversion of picosecond-long spin currents in magnetically ordered thin films. In this talk we will illustrate the manipulation of THz spin currents and their applied potential for magnetic switching in current ferromagnetic systems and propose a new strategy to transfer the ultrafast spintronic functionalities into fully compensated magnetic systems. Such a transfer could open pathways towards ultra-dense, fast and energy-efficient non-volatile memories that are beyond the reach of the established ferromagnetic technology.

5. prosince 2023
The Nobel Prize in Physics 2023: Experimental and Theoretical Aspects of Attosecond Physics
doc. RNDr. Martin Kozák, Ph.D. & Mgr. Zdeněk Mašín, Ph.D.
Department of Chemical Physics and Optics & Institute of Theoretical Physics, MFF Charles University
(seminář v angličtině)

The Nobel Prize in Physics 2023 was awarded to Pierre Agostini, Ferenc Krausz and Anne L'Huillier for the development of attosecond metrology, which has allowed to capture the dynamics of electrons in atoms, molecules and solids. We will review the most important experimental and theoretical concepts of this field of research.

12. prosince 2023
Non-local Relaxation Processes Following X-ray Irradiation of Solvated Ions
RNDr. Eva Muchová, Ph.D.
Department of Physical Chemistry, University of Chemistry and Technology, Prague
(seminář v angličtině)
X-rays can induce various processes in condensed systems ranging from radiation damage via formation of radicals and low-energy electrons or charge transfer processes to solvent. In my talk, I will focus on mechanisms of extensive, localized water ionization which can be caused by ultrafast processes following excitation by core-level ionization of hydrated metal ions. I will show a cascade of local Auger–Meitner and,importantly, non-local charge- and energy-transfer processes that involve water environment (electronic relaxation via electron transfer mediated decay (ETMD) processes). Furthermore, I will show that X-rays can also lead to the formation of charge transfer to solvent states from the solvated cations (Na+, Mg2+, and Al3+) to water.
19. prosince 2023
Christmas Talk on Polynomials
Mgr. Roman Čurík, Ph.D.
J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences
(seminář v angličtině)

At the beginning the talk will shortly connect two seemingly non-overlapping fields: the quantum scattering theory in physics and the mathematical theory of polynomials. After that the talk will follow a historical overview on the solvability of the polynomial equations by radicals. Starting from the Mesopotamian mathematical culture, through vigorous growth of mathematics in Renaissance, work of Newton, Lagrange, Vandermonde. The talk will finish in the 19th century when first Abel and then Galois have shown that it is impossible to solve the quintic equation by using no operations other than addition, subtraction, multiplication, division, and the extraction of roots. An introduction to the Galois theory will be presented with emphasis on the algebraic (or polynomial) equations and the groups associated with them.

Další ročníky:

© 7. prosince 2023; David Heyrovský <>
© 12. února 2024; vygenerováno pomocí aplikace seminar, verze 2.04 (2003-09-02); správce <>