Grad School Physics Seminar 2025/26

Name: Grad School Physics Seminar 2025/26
Start: 2025-10-02T09:15:00+02:00
End: 2026-06-26T18:00:00+02:00
Location: NCBJ

2 Oct 2025, 09:15 → 26 Jun 2026, 18:00 Europe/Warsaw

Room 207 (NCBJ)

Room 207

NCBJ

Pasteura 7

Description

Physics seminar of the Graduate School of NCBJ.

GoToMeeting link for the seminar: https://app.gotomeeting.com/?meetingId=434622613

Thursday, 9 October
- 09:15 → 09:35
  
  Welcoming Talk of the Graduate School Director¶ 20m
  
  Speaker: Prof. Michał Spaliński
- 09:35 → 09:55
  
  Discussion about the goals and organization of the PhD seminar¶ 20m
  
  Speakers: Anna Durkalec (National Centre for Nuclear Research), Jakub Wagner (National Centre for Nuclear Research), Michal Bluj (NCBJ)
  
  PHD SEMINARS.pdf
Thursday, 16 October
- 09:15 → 09:35
  
  Production of Self Interacting Scalars in the Early Universe 20m
  
  In this talk, I will present an overview of my research on Dark Matter (DM). I will begin with a brief introduction to the study of DM across different approaches, before focusing on Cannibal DM produced via the freeze-in mechanism in the early Universe. I will discuss the non-trivial thermal dynamics of this scenario and the importance of tracking the DM temperature evolution. I will then outline the resulting detectability prospects, which become viable in non-standard cosmological histories, particularly when the early Universe is dominated by a cold inflaton field. In the second part, I will turn to cosmological phase transitions, emphasizing how first-order transitions can generate observable gravitational waves (GWs). Finally, I will show that an inverse phase transition can occur within the freeze-in framework, where cannibalization dynamics crucially modify the evolution of the transition and the associated GW phenomenology, potentially within reach of future interferometer experiments.
  
  Speaker: Juan Esau Cervantes Hernandez (NCBJ Warsaw)
  
  dyskusja_phd_seminarium.pdf Self_Interacting_Scalars-EsauCervantes.pdf
Thursday, 23 October
- 09:15 → 09:35
  
  Study of direct photon production in Pb-Pb collisions at $\sqrt {s_{NN}}$ = 5.02 TeV with ALICE experiment’s Photon Spectrometer (PHOS) at Large Hadron Collider 20m
  
  The Quark-Gluon Plasma (QGP), a state of deconfined quarks and gluons, is believed to have existed in the early Universe shortly after the Big Bang. As the QGP cools, it transitions into the hadronic matter we observe today. In laboratory settings, small-scale "Big Bangs" are created through high-energy heavy-ion collisions, which heat the hadronic matter above the transition temperature, approximately 150 MeV, resulting in the formation of the QGP. Direct photons serve as unique probes in high-energy proton-proton and nucleus-nucleus collisions due to their weak interaction with the dense and hot quark-gluon medium. These photons escape the medium unaltered, providing undistorted information about the collision's evolution.
  In the ALICE experiment at the Large Hadron Collider (LHC), photons from lead-lead collisions are measured using techniques such as the Photon Conversion Method and Electromagnetic Calorimeter. The Photon Spectrometer (PHOS), offering high-precision photon detection, was used for our analysis (with Run 2 data in Pb-Pb collisions at $\sqrt {s_{NN}}$ = 5.02 TeV) to measure inclusive photons and simulate decay photons, aiding in the derivation of direct photon spectra. By disentangling the contributions of decay, prompt and thermal photons emitted during these collisions, we can estimate the effects of cold and hot nuclear matter and gain insights into the temperature, correlations, and collective phenomena within the QGP.
  
  Speaker: Sushobhan Mandal (NCBJ)
  
  Direct_photon_SM_23Oct25.pdf
Thursday, 30 October
- 09:15 → 10:15
  
  CMB Lensing with TEReSiTA 1h
  
  We are currently living in the most scientifically active era of the human kind: cosmology makes no exception. Our understanding of the Universe has radically changed during the last decades. However, while many long-standing questions about the nature of the Universe have been answered, many others have emerged. Why is the Universe's expansion accelerating? What is dark energy? What is dark matter? How does inflation work?
  The study of the Cosmic Microwave Background, together with other cosmological probes, is one of the ways we can answer these new questions. In particular, studying the weak gravitational lensing effect of large-scale structure on the CMB photons, we can obtain information about both the primordial and the late-time Universe. I will show how.
  In this talk, I present the Tomographic Ensamble of Realistic Simulations of Tracers and Anisotropies (TEReSiTA): a set of simulations of correlated galaxy catalogues and CMB observations. TEReSiTA, my original work, is a very useful and versatile tool for testing new paths in the quest for high-precision cosmological parameter estimation.
  
  Speaker: Nicola Principi (NCBJ)
  
  principi_phd_seminar.pdf

Grad School Physics Seminar 2025/26

Room 207

NCBJ

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