Exponential potential for an inflaton with nonminimal kinetic coupling and its supergravity embedding

TL;DR

This paper explores exponential inflationary potentials with nonminimal kinetic coupling to Einstein gravity, demonstrating their observational viability, natural exit mechanism, and embedding within supergravity as effective dilaton theories.

Contribution

It introduces a model with nonminimal kinetic coupling for exponential potentials, showing compatibility with observations and a natural exit from inflation, along with supergravity embedding.

Findings

Exponential potentials with kinetic coupling fit observational data.

The model provides a natural exit from inflation without a minimum.

Supergravity embedding suggests a dilaton interpretation.

Abstract

In the light of the new observational results we discuss the status of the exponential potentials driving inflation. We depart form the minimal scenario and study an inflaton kinetically coupled to the Einstein tensor. We find that in this case the exponential potentials are well compatible with observations. Their predictions coincide with those of the chaotic type quadratic potential for an inflaton minimally coupled to gravity. We show that there exists a simple mapping between the two models. Moreover, a novel aspect of our model is that it features a natural exit from the inflationary phase even in the absence of a minimum. We also turn to supergravity and motivate these sort of potentials and the non-minimal kinetic coupling as possible effective dilaton theories.