Saddle point inflation in string-inspired theory

TL;DR

This paper explores saddle point inflation within string-inspired, non-supersymmetric theories, proposing the Higgs field as the inflaton and fixing the string scale around the GUT scale for successful inflation.

Contribution

It demonstrates that the Higgs can serve as the inflaton in string-inspired models without supersymmetry, fixing the string scale near the GUT scale.

Findings

The string scale is around 10^{16} GeV for successful inflation.

The Higgs field can naturally be identified as the inflaton.

Saddle point inflation can be realized in non-supersymmetric string-inspired theories.

Abstract

The observed value of the Higgs mass indicates the possibility that there is no supersymmetry below the Planck scale and that the Higgs can play the role of the inflaton. We examine the general structure of the saddle point inflation in string-inspired theory without supersymmetry. We point out that the string scale is fixed to be around the GUT scale $\sim10^{16}$GeV in order to realize successful inflation. We find that the inflaton can be naturally identified with the Higgs field.