Brane Cosmological Evolution With Bulk Matter

TL;DR

This paper explores brane cosmology with bulk matter, deriving exact solutions that show accelerated expansion and allow the dark energy equation of state to cross w=-1 without exotic matter.

Contribution

It introduces a phenomenological approach to bulk matter in brane cosmology and finds exact solutions demonstrating accelerated expansion and w=-1 crossing.

Findings

Exact solutions with accelerated expansion

Dark energy equation of state crosses w=-1

Bulk matter influences brane cosmological dynamics

Abstract

We consider the cosmological evolution of a brane for general bulk matter content. In our setup the bulk pressure and the energy exchange densities are comparable to the brane energy density. Adopting a phenomenological fluid ansatz and generalizations of it, we derive a set of exact solutions of the Friedmann equation that exhibit accelerated expansion. We find that the effective equation of state parameter for the dark energy can exhibit w=-1 crossing without the presence of exotic matter.