Gauss-Bonnet-induced symmetry breaking/restoration during inflation

TL;DR

This paper introduces a mechanism during inflation where the Gauss-Bonnet term coupled to a charged scalar can cause symmetry breaking or restoration, affecting inflationary dynamics without altering predictions.

Contribution

It presents a novel process of symmetry change during inflation driven by Gauss-Bonnet coupling, with conditions ensuring minimal backreaction on inflationary predictions.

Findings

Gauss-Bonnet coupling induces inflaton-dependent scalar mass sign change

Symmetry can be spontaneously broken or restored during inflation

Backreaction can be negligible, preserving inflationary predictions

Abstract

We propose a mechanism of symmetry breaking or restoration that can occur in the middle of inflation due to the coupling of the Gauss-Bonnet term to a charged scalar. The Gauss-Bonnet coupling results in an inflaton-dependent effective squared mass of the charged scalar, which can change its sign (around the symmetric point) during inflation. This can lead to spontaneous breaking of the symmetry, or to its restoration, if it is initially broken. We show the conditions under which the backreaction of the Gauss-Bonnet coupling on the inflationary background is negligible, such that the predictions of a given inflationary model are unaffected by the symmetry breaking/restoration process.