Collision Integrals for Cosmological Phase Transitions

Abstract

The dynamics of the true-vacuum bubbles nucleated during a first-order phase transition is affected by the distribution functions of the particle species in the plasma, driven out-of-equilibrium by the travelling domain wall. An accurate modelling of this phenomenon is relevant for a quantitative description of phase transitions in the early universe and for the determination of the corresponding cosmic relics, such as, among the others, the stochastic background of gravitational waves. We address this problem by developing a new spectral method devised for a fast and reliable computation of the collision integral in the Boltzmann equations. In a scalar singlet extension of the Standard Model chosen as a benchmark scenario, we test our algorithm, determining the bubble speed and profile, and we asses the impact of the out-of-equilibrium dynamics.

18 pages, 3 figures

References in corpus (7)

• Bubble wall dynamics at the electroweak phase transition
• Hydrodynamic obstruction to bubble expansion
• A sonic boom in bubble wall friction
• Hydrodynamics of phase transition fronts and the speed of sound in the plasma
• Stability of cosmological detonation fronts
• Lower bound on the electroweak wall velocity from hydrodynamic instability
• Dynamics of bubble walls at the electroweak phase transition