Chameleons on the Racetrack

TL;DR

This paper proposes a modified string theory model with a racetrack superpotential for chameleon scalars, satisfying experimental constraints and allowing the chameleon to be light enough for cosmological relevance.

Contribution

It introduces a racetrack superpotential with two exponentials, enhancing the viability of chameleon models within string theory frameworks.

Findings

Model satisfies all experimental constraints.

Chameleon remains light on cosmological scales.

Potential for phenomenological applications.

Abstract

We modify the ansatz for embedding chameleon scalars in string theory proposed in [1] by considering a racetrack superpotential with two KKLT-type exponentials $e^{ia\varrho}$ instead of one. This satisfies all experimental constraints, while also allowing for the chameleon to be light enough on cosmological scales to be phenomenologically interesting.