Gauss-Bonnet Term on Vacuum Decay

TL;DR

This paper investigates how the Gauss-Bonnet term, coupled exponentially to a scalar field, influences vacuum decay processes within the Coleman-De Luccia framework, revealing its significant impact depending on the coupling strength.

Contribution

It provides a numerical analysis of instanton solutions with the Gauss-Bonnet term and explores its effect on the critical bubble size in vacuum decay.

Findings

Gauss-Bonnet term affects false vacuum decay rates

Critical bubble size varies with Gauss-Bonnet coefficient

Nontrivial influence depending on coupling strength

Abstract

We study the effect of the Gauss-Bonnet term on vacuum decay process in the Coleman-De Luccia formalism. The Gauss-Bonnet term has an exponential coupling with the real scalar field, which appears in the low energy effective action of string theories. We calculate numerically the instanton solution, which describes the process of vacuum decay, and obtain the critical size of bubble. We find that the Gauss-Bonnet term has a nontrivial effect on the false vacuum decay, depending on the Gauss-Bonnet coefficient.