p-Brane cosmology and phases of Brans-Dicke theory with matter

TL;DR

This paper explores how solitonic p-branes influence string cosmology by deriving exact solutions within a Brans-Dicke framework, analyzing different matter equations of state and their cosmological implications.

Contribution

It provides a comprehensive classification of cosmological solutions for arbitrary Brans-Dicke parameters and matter equations of state, extending previous models.

Findings

Exact solutions for any Brans-Dicke parameter $$ and equation of state parameter $$.

Classification of cosmological behaviors based on parameter space.

Insights into the role of solitonic p-branes in string cosmology.

Abstract

We study the effect of the solitonic degrees of freedom in string cosmology following the line of Rama. The gas of solitonic p-brane is treated as a perfect fluid in a Brans-Dicke type theory. In this paper, we find exact cosmological solutions for any Brans-Dicke parameter $\omega$ and for general parameter $\gamma$ of equation of state and classify the cosmology of the solutions on a parameter space of $\gamma$ and $\omega$.