Phase Transitions at Preheating

TL;DR

This paper investigates how symmetry restoration during preheating after inflation can be highly efficient, with effects comparable to extremely high temperatures, impacting GUT and axion models.

Contribution

It demonstrates that symmetry restoration during preheating can be much more effective than previously thought, reaching temperatures near the Planck scale in some models.

Findings

Symmetry restoration efficiency increases with low-energy particle concentration.

Effective temperatures during preheating can surpass equilibrium temperatures by many orders of magnitude.

Potential implications for GUT and axion models due to high effective temperatures.

Abstract

Symmetry restoration processes during the non-equilibrium stage of ``preheating'' after inflation is studied. It is shown that symmetry restoration is very efficient when the majority of created particles are concentrated at energies much smaller than the temperature $T$ in equilibrium. The strength of symmetry restoration measured in terms of the equivalent temperature can exceed $T$ by many orders of magnitude. In some models the effect can be equivalent to that if the temperature of instant reheating would be close to the Planck scale. This can have an important impact on GUT and axion models.