Inflation and Kahler Stabilization of the Dilaton

TL;DR

This paper investigates how the dilaton in string theory can be stabilized during inflation through Kahler potential corrections, ensuring consistent GUT scale coupling and spectral index predictions.

Contribution

It demonstrates that dilaton stabilization during inflation is feasible in heterotic string models with Kahler potential corrections, linking it to supersymmetry structure.

Findings

Dilaton remains close to today's value during inflation.

Stabilization is compatible with GUT scale coupling.

Supports standard spectral index predictions.

Abstract

The problems of attempting inflationary model-building in a theory containing a dilaton are explained. In particular, I study the shape of the dilaton potential today and during inflation, based on a weakly-coupled heterotic string model where corrections to the Kahler potential are assumed to be responsible for dilaton stabilization. Although no specific model-building is attempted, if the inflationary energy density is related to the scale of gaugino condensation, then the dilaton may be stabilized close enough to today's value that there is no significant change in the GUT scale coupling. This can occur in a very wide range of models, and helps to provide some justification for the standard predictions of the spectral index. I explain how this result can ultimately be traced to the supersymmetry structure of the theory.