Bubble wall dynamics at the electroweak phase transition

Abstract

First order phase transitions could play a major role in the early universe, providing important phenomenological consequences, such as the production of gravitational waves and the generation of baryon asymmetry. An important aspect that determines the properties of the phase transition is the dynamics of the true-vacuum bubbles, which is controlled by the density perturbations in the hot plasma. We study this aspect presenting, for the first time, the full solution of the linearized Boltzmann equation for the top quark species coupled to the Higgs field during a first-order electroweak phase transition. Our approach, differently from the traditional one based on the fluid approximation, does not rely on any ansatz and can fully capture the density perturbations in the plasma. We find that our results significantly differ from the ones obtained in the fluid approximation (including its extensions and modifications), both at the qualitative and quantitative level. In particular sizable differences are found for the friction acting on the bubble wall.

25 pages, 24 figures

References in corpus (9)

• Bubble wall velocity: heavy physics effects
• From Boltzmann equations to steady wall velocities
• A sonic boom in bubble wall friction
• Hydrodynamics of phase transition fronts and the speed of sound in the plasma
• Effective picture of bubble expansion
• An efficient approach to electroweak bubble velocities
• Bubble wall velocity beyond leading-log approximation in electroweak phase transition
• Stability of cosmological detonation fronts
• Lower bound on the electroweak wall velocity from hydrodynamic instability