Cosmic Evolution in Brans-Dicke Chameleon Cosmology

TL;DR

This paper explores exact solutions in Brans-Dicke Chameleon cosmology, analyzing cosmic evolution without acceleration, and examines related cosmological parameters and distances.

Contribution

It provides new exact solutions for scale factor, scalar field, and interaction functions in Brans-Dicke Chameleon gravity across different cosmic epochs.

Findings

No accelerating solutions found, only decelerating expansion.

Analyzed cosmological distances and statefinder parameters.

Discussed behavior of deceleration parameter in the model.

Abstract

We have investigated the Brans-Dicke Chameleon theory of gravity and obtained exact solutions of the scale factor $a(t)$, scalar field $\phi(t)$, an arbitrary function $f(\phi)$ which interact with the matter Lagrangian in the action of the Brans-Dicke Chameleon theory and potential $V(\phi)$ for different epochs of the cosmic evolution. We plot the functions $a(t)$, $\phi(t)$, $f(t)$ and $V(\phi)$ for different values of the Brans-Dicke parameter. In our models, there is no accelerating solution, only decelerating one with $q>0$. The physical cosmological distances have been investigated carefully. Further the statefinder parameters pair and deceleration parameter are discussed.