Higgs Inflation with a Gauss-Bonnet term in the Jordan Frame

TL;DR

This paper investigates how coupling the Higgs field to a Gauss-Bonnet term affects Higgs inflation, finding that while predictions remain robust, the end of inflation and reheating processes could be significantly altered, raising questions about the model's viability.

Contribution

It introduces a Higgs inflation model with a Gauss-Bonnet coupling analyzed solely in the Jordan frame, highlighting effects on inflation end and reheating.

Findings

Predictions of Higgs inflation are robust despite the Gauss-Bonnet coupling.

The Gauss-Bonnet term's contribution to power spectra is negligible.

The end of inflation and reheating dynamics can be significantly modified.

Abstract

We consider an extension of Higgs inflation in which the Higgs field is coupled to the Gauss-Bonnet term. Working solely in the Jordan frame, we firstly recover the standard predictions of Higgs inflation without a Gauss-Bonnet term. We then calculate the power spectra for scalar and tensor perturbations in the presence of a coupling to a Gauss-Bonnet term. We show that generically the predictions of Higgs inflation are robust and the contributions to the power spectra coming from the Gauss-Bonnet term are negligible. We find, however, that the end of inflation can be strongly modified and that we hence expect the details of (p)reheating to be significantly altered, leading to some concerns over the feasibility of the model which require further investigations.