Seminarium "Teoria cząstek elementarnych i kosmologia"
2017/2018 | 2018/2019 | 2019/2020 | 2020/2021 | 2021/2022 | 2022/2023 | 2023/2024 | 2024/2025 | 2025/2026
2026-01-15 (Czwartek)
Zapraszamy do sali 1.01, ul. Pasteura 5 o godzinie 12:15 
Peter Matak (Comenius University in Bratislava)From cutting rules to minimal effective theory for leptogenesis, dark matter, and neutrino masses
In the first part of the seminar, we will use unitarity and the optical theorem to build an effective theory that simultaneously explains the matter–antimatter asymmetry via leptogenesis, the dark matter relic abundance via freeze-in or freeze-out mechanisms, and neutrino masses via the Weinberg operator. We will show that, in a minimal scenario, only two new particles and a single portal operator coupling the visible and dark sectors are sufficient beyond the Standard Model. In the second part, we will focus on interpreting the non‑standard asymmetry contributions which, as we demonstrate, must be included. We will present an algorithm designed to avoid the most common mistakes and inconsistencies when calculating an asymmetry source term in the Boltzmann equation.
2026-01-08 (Czwartek)
Zapraszamy do sali 1.01, ul. Pasteura 5 o godzinie 12:15
Daniele Perri (IFT UW)Magnetic monopoles as dark matter: are they still alive?
Magnetic monopoles are a long-sought prediction of Grand Unified Theories (GUTs). However, their efficient production in the early universe would result in an abundance far exceeding observational bounds — a challenge known as the cosmological monopole problem. The standard solution invokes an inflationary phase occurring after monopole formation, which dilutes their density, while removing any possibility of their present-day detection. In this talk, I will review the current status of monopoles as dark matter, demonstrating how there is still a window where even GUT monopoles can serve as viable dark matter candidates. I will also present an alternative solution to the monopole problem based on a minimal breaking of conformal symmetry in the gauge kinetic sector. The proposed mechanism enhances monopole annihilation, reducing their relic abundance to acceptable levels potentially within the reach of current and upcoming cosmic-ray detection experiments.