Exponentially Expanding Radiation Dominated and Dust Dominated Universes in Brans-Dicke Theory

TL;DR

This paper explores solutions in Brans-Dicke gravity where the universe's scale factor and scalar field grow exponentially over time, considering a modified action with unconventional signs for kinetic and mass terms.

Contribution

It introduces new exponential solutions in Brans-Dicke theory with altered scalar field action terms, expanding understanding of possible cosmological behaviors.

Findings

Exponential solutions for scale factor and scalar field found

Modified action terms lead to unique cosmological solutions

Results suggest alternative dynamics in Brans-Dicke cosmology

Abstract

The Brans-Dicke Theory of Gravity is one of the most promising alternatives to the Einstein's Theory of General Relativity. We have examined an action term with wrong signs for both the kinetic and mass terms for the scalar field and have found solutions for both the scale factor of the universe and the Brans-Dicke scalar field which vary exponentially in time.