Supercooling exit from charge supersaturation

TL;DR

This paper explores how a conserved charge and chemical potential can enable a scalar field system to escape supercooling and transition from a metastable to a stable vacuum during cosmic evolution.

Contribution

It introduces a mechanism where chemical potential effects facilitate phase transition in scalar fields with metastable potentials, addressing supercooling issues.

Findings

Chemical potential can trigger phase transition from metastable to stable vacuum.

Decoupling of species alters the balance between temperature and chemical potential effects.

Mechanism provides a new way to escape supercooling in cosmological models.

Abstract

Systems that feature a scalar field $\phi$ with a quasi scale invariant potential, metastable at $\phi=0$, can remain trapped, during cosmic evolution, in the `wrong' vacuum because the process of bubble nucleation to the true vacuum is inefficient. If $\phi$ carries a conserved charge $Q$, the presence in the system of a non-zero chemical potential for $Q$ offers the possibility of escaping eternal supercooling: when a species decouples from the plasma the balance among the stabilising effect of temperature and the destabilising effect of chemical potential can change in favour of the latter, so that $\phi$ condenses and triggers the transition to the stable phase.