Seminarium "Teoria cząstek elementarnych i kosmologia"
2017/2018 | 2018/2019 | 2019/2020 | 2020/2021 | 2021/2022 | 2022/2023 | 2023/2024 | 2024/2025 | 2025/2026
2025-10-16 (Czwartek)
Zapraszamy do sali 1.01, ul. Pasteura 5 o godzinie 12:15 
Maciej Kierkla (IFT UW)Finite-temperature bubble-nucleation with shifting scale hierarchies
Focusing on supercooled PTs in models with classical scale symmetry, we investigate the limitations of derivative expansions in constructing a thermal EFT description for bubble nucleation. We show that the derivative expansion for gauge field fluctuations diverges because the gauge field mass varies strongly between the high- and low-temperature phases. By computing the gauge fluctuation determinant, we show that these effects can be captured while accounting for large explicit logarithms at two loops. We show how this construction can improve nucleation rate calculations, providing a more robust framework for describing GW from supercooled PT in models like the SU(2)cSM.
2025-10-09 (Czwartek)
Zapraszamy do sali 1.01, ul. Pasteura 5 o godzinie 12:15
Jorinde van de Vis (CERN)The bubble wall velocity in cosmological phase transitions
Cosmological first order phase transitions are a promising source of gravitational waves, and a possible explanation of the baryon asymmetry and dark matter abundance. Predicting the phenomenological consequences of such phase transitions requires knowledge of the expansion velocity of the bubbles formed in a phase transition. In this talk, I will summarize the computation of the wall velocity and present WallGo, a software package for the computation of bubble wall velocities. WallGo is the first publicly available code that computes the matrix elements, collision integrals Boltzmann equation and scalar field equation of motion for user-defined models. I will present results obtained with WallGo, and discuss estimates of the theoretical uncertainty of the bubble wall velocity. I will end with an estimate of the wall velocity in theories with strong coupling.
2025-10-02 (Czwartek)
Zapraszamy do sali 1.01, ul. Pasteura 5 o godzinie 12:15
Ayuki Kamada (IFT UW)Decay of scalar condensation: two different approaches
Scalar condensation and its decay plays important roles in cosmology.A notable example is inflation and reheating driven by inflaton condensation and its decay. Two approaches can be found in literatures, in computing the decay (damping) rate of coherently oscillating scalar. One is based on the parametric resonance in a mode function of a daughter particle. The other is based on the effective action in the presence of a background field. In this talk, we see that these two approaches look very different in the course of computation, but actually give the same decay rate.