Non-Equilibrium Phase Transitions and Domain Walls

TL;DR

This paper investigates non-equilibrium phase transitions in scalar fields within expanding spacetime, revealing how biased vacuum choices influence domain wall formation and decay, with implications for cosmological models.

Contribution

It introduces an analytical framework using percolation theory to describe vacuum bias effects and provides computer simulations of domain wall evolution in non-equilibrium conditions.

Findings

Biased systems form domain walls that decay exponentially.

Non-equilibrium transitions differ from thermal equilibrium behavior.

Results suggest new perspectives on cosmological domain walls.

Abstract

Non-equilibrium phase transitions of a scalar field in an expanding spacetime are discussed. These transitions are shown to lead, for appropriate potential energy functions, to a biased choice of vacuum structure which can be analytically described using percolation theory. The initial domain wall networks, which form between different vacua, are evolved in time by computer simulation and their behavior analyzed. It is shown that, unlike systems in thermal equilibrium, domain walls formed in biased systems persist for only a short time before decaying exponentially away. This result opens the door to a re-analysis of domain walls in cosmology.