Chameleonic inflation

TL;DR

This paper explores embedding inflation within a string theory-based chameleon model, requiring large extra dimensions and a modified Kahler potential, with a potential that supports both early universe inflation and late-time chameleon screening.

Contribution

It demonstrates a novel string theory framework that unifies inflation and chameleon screening through a two-part potential with a large flat desert in field space.

Findings

A large extra dimensions setup is necessary.

A semi-phenomenological deformation of the Kahler potential is required.

The potential can support scalar field traversal from inflation to late-time screening.

Abstract

We attempt to incorporate inflation into a string theory realization of the chameleon mechanism. Previously, it was found that the volume modulus, stabilized by the supersymmetric potential used by Kachru, Kallosh, Linde and Trivedi (KKLT) and with the right choice of parameters, can generically work as a chameleon. In this paper, we ask whether inflation can be realized in the same model. We find that we need a large extra dimensions set-up, as well as a semi-phenomenological deformation of the Kahler potential in the quantum region. We also find that an additional KKLT term is required so that there are now two pieces to the potential, one which drives inflation in the early universe, and one which is responsible for chameleon screening at late times. These two pieces of the potential are separated by a large flat desert in field space. The scalar field must dynamically traverse this desert between the end of inflation and today, and we find that this can indeed occur under the right conditions.