Brans-Dicke Scalar Field as a Chameleon

TL;DR

This paper demonstrates that a non-minimal coupling in Brans-Dicke theory can produce a universe that transitions from decelerated to accelerated expansion, depending on the Brans-Dicke parameter.

Contribution

It introduces a model where a non-minimal matter-scalar coupling in Brans-Dicke theory leads to late-time cosmic acceleration.

Findings

Non-minimal coupling induces accelerated expansion

Decelerated early universe transitions to acceleration

Behavior depends on the Brans-Dicke parameter 

Abstract

In this paper it is shown that in Brans - Dicke theory, if one considers a non-minimal coupling between the matter and the scalar field, it can give rise to a late time accelerated expansion for the universe preceded by a decelerated expansion for very high values of the Brans - Dicke parameter $\omega$.