Cosmological First-Order Phase Transitions and Bubble Wall Dynamics

by Dr Wen-Yuan Ai (Österreichische Akademie der Wissenschaften)

Wednesday 11 Jun 2025, 14:00 → 15:00 Europe/Berlin

3343 Handbibliothek Theorie (TUM Physik-Department)

First-order phase transitions (FOPTs) are a compelling source of stochastic gravitational wave backgrounds, and, meanwhile, have significant phenomenological implications. Central to nearly all FOPT-related phenomena is the dynamics of bubble expansion, particularly the bubble wall terminal velocity. In this talk, I will discuss bubble wall dynamics from multiple perspectives, including an efficient method for computing the wall velocity using the local thermal equilibrium approximation, as well as a more precise understanding based on non-equilibrium quantum field theory. I will also briefly discuss a relatively new application of FOPTs: heavy dark matter production from ultra-relativistic bubble walls.