On Winding Branes and Cosmological Evolution of Extra Dimensions in String Theory

TL;DR

This paper investigates how wrapped branes influence the evolution of extra dimensions in string cosmology, revealing that a single brane wrapping all extra dimensions offers the most viable scenario for their stabilization.

Contribution

It provides exact solutions for winding brane gases in cosmology and analyzes their role in the evolution of extra dimensions, including T-duality invariance in dilaton gravity.

Findings

Wrapped branes can hinder the expansion of extra dimensions.

A single brane wrapping all extra dimensions is most phenomenologically viable.

T-duality invariance is established in dilaton gravity solutions.

Abstract

We consider evolution of compact extra dimensions in cosmology and try to see whether wrapped branes can prevent the expansion of the internal space. Some difficulties of Brandenberger and Vafa mechanism for decompactification are pointed out. In both pure Einstein and dilaton gravities, we study cosmology of winding brane gases in a continuum approximation. The energy momentum tensor is obtained by coupling the brane action to the gravity action and we present several exact solutions for various brane configurations. T-duality invariance of the solutions are established in dilaton gravity. Our results indicate that phenomenologically the most viable scenario can be realized when there is only one brane wrapping over all extra dimensions.