Month: May 2018

Graduate Seminar, 4th June

Speaker: Viktor Svensson

Title: Tensor Network techniques for many-body systems

Abstract: In quantum many-body systems of even moderate sizes, Hilbert space is far too large to fit on a computer. This makes numerical calculations a challenge. With the use of tensor networks, certain classes of quantum states can be efficiently represented and computed. In this talk, I will give an introduction to tensor networks and what they are good for.

 

Graduate Seminar, 28th May

Speaker:  Oleksandr Kovalenko

Title: Experimental tests of perturbative Quantum Chromodynamics

Abstract:  The Deep Inelastic Scattering and Drell-Yan processes can’t be directly calculated. The factorization concept assumes that the cross sections of these processes can be expressed as a convolution of parton distribution functions and fragmentation functions (FFs). These functions can’t be obtained from the theory and require an input form the experiment. The seminar will be focused on the techniques that are used to extract the FFs for pp and ep collisions. The comparison of theoretical estimates of FFs and the most recent experimental results on neutral meson spectra will be given.

Graduate Seminar, 21st May

Speaker: Erik Kofoed

Title:  Asymptotic Freedom at Finite Temperatures and Densities

Abstract: It is well known fact that the strong coupling constant in quantum chromodynamics (QCD) becomes weak at high energies which allows for perturbative calculations using Feynman diagrams. This is the phenomenon of asymptotic freedom. Much less clear is the status of asymptotic freedom at the early stages of a heavy ion collision where a bulk QCD medium is present. One difficulty is that there is, unlike in vacuum, no ‘best’ definition of what we mean with a coupling constant. The analysis is also complicated by the fact that a medium is characterised by several dimensionful scales, making the powerful scaling relations that can be used in vacuum not applicable

Thesis topic proposal

Dark matter: theoretical models, particle candidates and prospects of their experimental discovery

The Particle Theory Group led by Prof. Leszek Roszkowski invites applications for a 4- year PhD studentship at the National Centre for Nuclear Research (NCBJ). The studentship is funded by National Science Centre (Narodowe Centrum Nauki, NCN) within the Maestro grant “Dark matter: theoretical models, particle candidates and prospects of their experimental discovery”.

Graduate Seminar, 14th May

Speaker: Artem Poliszczuk

Title: Searching for AGNs in the infrared data

Abstract: In the era of big data driven astronomy creating trustable catalogs of astronomical objects plays crucial role in observational cosmology. In particular, Active Galactic Nuclei (AGN) catalogs still cause many difficulties for the observers. In my presentation I will briefly discuss the general properties of different types of AGNs and focus on their identification in the infrared passbands due to the high AGN selection efficiency in this part of the spectrum.