Self interacting Brans Dicke cosmology and Quintessence

TL;DR

This paper explores a self-interacting Brans-Dicke cosmological model with a perfect fluid, identifying a positive power-law potential that supports accelerated expansion and analyzing density perturbations for negative coupling parameters.

Contribution

It demonstrates that a positive power-law potential in self-interacting Brans-Dicke theory can produce accelerated expansion and supports growing density perturbations for negative coupling.

Findings

Positive power-law potential drives accelerated expansion for negative ω

Model supports growing density perturbations with negative ω

Potential compatibility with flat, accelerating universe observations

Abstract

Recent cosmological observations reveal that we are living in a flat accelerated expanding universe. In this work we have investigated the nature of the potential compatible with the power law expansion of the universe in a self interacting Brans Dicke cosmology with a perfect fluid background and have analyzed whether this potential supports the accelerated expansion. It is found that positive power law potential is relevant in this scenario and can drive accelerated expansion for negative Brans Dicke coupling parameter $\omega$. The evolution of the density perturbation is also analyzed in this scenerio and is seen that the model allows growing modes for negative $\omega$.