Seminarium "Teoria cząstek elementarnych i kosmologia"

Cosmological phase transitions can give rise to intriguing phenomena, such as baryogenesis or a stochastic gravitational wave background, due to nucleation and percolation of vacuum bubbles in the primordial plasma. A key parameter for predicting these relics is the bubble wall velocity, whose computation relies on solving the Boltzmann equations of the various species along the bubble profile. I will discuss how we can find this wall velocity by solving the Boltzmann equation, and how we can treat the singularities that arise in the out-of-equilibrium terms that govern the process.