Hydrodynamic obstruction to bubble expansion

TL;DR

This paper investigates how hydrodynamic effects, specifically plasma heating in compression waves, can hinder bubble wall acceleration during a cosmological phase transition, impacting scenarios like electroweak baryogenesis.

Contribution

It introduces a simple criterion to determine when hydrodynamic obstruction occurs at subsonic bubble wall velocities in first-order phase transitions.

Findings

Hydrodynamic obstruction can prevent bubble wall acceleration.

The criterion relates critical temperature, transition temperature, and latent heat.

Subsonic bubble velocities are achievable under certain conditions.

Abstract

We discuss a hydrodynamic obstruction to bubble wall acceleration during a cosmological first-order phase transition. The obstruction results from the heating of the plasma in the compression wave in front of the phase transition boundary. We provide a simple criterion for the occurrence of the obstruction at subsonic bubble wall velocity in terms of the critical temperature, the phase transition temperature, and the latent heat of the model under consideration. The criterion serves as a sufficient condition of subsonic bubble wall velocities as required by electroweak baryogenesis.