Small field inflation in ${\cal N}=1$ supergravity with a single chiral superfield

TL;DR

This paper explores small field inflation models within minimal ${ m N}=1$ supergravity, classifying viable models under experimental constraints and examining the special case where the inflaton is a large volume modulus.

Contribution

It provides a classification of small field inflation models in ${ m N}=1$ supergravity with a single chiral superfield, highlighting the restrictions imposed by observational data and specific field behavior.

Findings

Most models are severely restricted by experimental constraints.

Viable models with large field values require highly contrived superpotentials.

The inflaton as a volume modulus leads to very specific superpotential forms.

Abstract

We consider "new inflation" inflationary models at small fields, embedded in minimal ${\cal N}=1$ supergravity with a single chiral superfield. Imposing a period of inflation compatible with experiment severely restricts possible models, classified in perturbation theory. If moreover we impose that the field goes to large values and very small potential at the current time, like would be needed for instance for the inflaton being the volume modulus in large extra dimensional scenarios, the possible models are restricted to very contrived superpotentials.