Cosmology of Randall-Sundrum models with an extra dimension stabilized by balancing bulk matter

TL;DR

This paper develops cosmological solutions for Randall-Sundrum models with stabilized extra dimensions via bulk matter, enabling consistent brane cosmology and addressing the cosmological constant problem.

Contribution

It introduces a specific bulk energy-momentum component that stabilizes the extra dimension and modifies the Friedmann equation, allowing for realistic brane cosmology.

Findings

Stabilization of the extra dimension with bulk matter.

Resolution of the Friedmann equation sign issue for negative tension branes.

Reproduction of standard FRW cosmology on the brane.

Abstract

We provide the cosmological solutions for Randall-Sundrum models with the bulk energy-momentum $\hat T^5_5$ incorporated. It alters the Friedmann equation for the brane scale factor. We make a specific choice of $\hat T^5_5$ which is adjusted to stabilize the extra dimension. This makes it possible to compactify the extra dimension with a single positive tension brane, and this model provides a RS-type solution to the cosmological constant problem. When the same idea is applied to the RS model with two branes, the wrong sign of Friedmann equation for the negative tension brane can be resolved and usual FRW cosmology is reproduced for the brane.