Chameleon field and the late time acceleration of the universe

TL;DR

This paper demonstrates that a chameleon scalar field with nonminimal coupling to dark matter can drive the universe's transition from deceleration to acceleration without significantly altering dark matter evolution.

Contribution

It introduces a model where a chameleon scalar field induces late-time cosmic acceleration while minimally impacting dark matter behavior.

Findings

Chameleon field causes transition to accelerated expansion.

Dark matter density evolution remains nearly unaffected.

Model aligns with observed late-time acceleration.

Abstract

In the present work, it is shown that a chameleon scalar field having a nonminimal coupling with dark matter can give rise to a smooth transition from a decelerated to an accelerated phase of expansion for the universe. It is surprising to note that the coupling with the chameleon scalar field hardly affects the evolution of the dark matter sector, which still redshifts as $a^{-3}$.