Chameleon Field Dynamics During Inflation

TL;DR

This paper investigates the viability of the chameleon scalar field as an inflationary model, analyzing its dynamics and constraints, and concludes it is unlikely to successfully drive inflation without additional mechanisms.

Contribution

The study applies slow-roll approximations to the chameleon model with typical potentials to assess its potential as an inflationary scenario, providing new insights into its limitations.

Findings

Chameleon inflation is unlikely to succeed under standard conditions.

Constraints on potential and equation of state restrict chameleon inflation.

Additional mechanisms may be needed for chameleon to unify inflation and late-time acceleration.

Abstract

By studying the chameleon model during inflation, we investigate whether it can be a successful inflationary model, wherein we employ the common typical potential usually used in the literature. Thus, in the context of the slow-roll approximations, we obtain the number of e-folding for the model to verify the ability of resolving the problems of standard big bang cosmology. Meanwhile, we apply the constraints on the form of the chosen potential and also on the equation of state parameter coupled to the scalar field. However, the results of the present analysis show that there is not much chance of having the chameleonic inflation. Hence, we suggest that if through some mechanism the chameleon model can be reduced to the standard inflationary model, then it may cover the whole era of the universe from the inflation up to the late time.