Quintessence in brane cosmology

TL;DR

This paper explores how introducing a slowly-varying quintessence scalar field in brane cosmology can reconcile it with standard Friedmann cosmology, proposing alternative compensation mechanisms for the cosmological constant.

Contribution

It presents new mechanisms involving quintessence fields and bulk cosmological constants to achieve a more conventional accelerating universe in brane cosmology.

Findings

Different compensation mechanisms are identified for the cosmological constant.

The Randall-Sundrum approach is not the only way to reconcile brane and standard cosmologies.

An alternative mechanism reproduces an accelerating universe with conventional behavior.

Abstract

In order to reconcile the non conventional character of brane cosmology with standard Friedmann cosmology, we introduce in this paper a slowly-varying quintessence scalar field in the brane and analyse the cosmological solutions corresponding to some equations of state for the scalar field. Different compensation mechanisms between the cosmological constant in the bulk and the constant tension resulting from the combined effect of ordinary matter and the quintessence scalar field are derived or assumed. It has been checked that the Randall-Sundrum approach is not necessarily the best procedure to reconcile brane and standard cosmologies, and that there exists at least another compensating mechanism that reproduces a rather conventional behaviour for an accelerating universe.