Wrapped Branes and Compact Extra Dimensions in Cosmology

TL;DR

This paper proposes a cosmological model with extra dimensions wrapped by p-branes, showing that the observable universe expands while extra dimensions contract, potentially explaining their small size.

Contribution

It introduces a higher-dimensional cosmological model with wrapped branes that naturally accounts for the small size of extra dimensions.

Findings

Observable universe expands as pressureless matter

Extra dimensions contract during evolution

Model supports small size of extra dimensions

Abstract

We present a cosmological model in 1+m+p dimensions, where in m-dimensional space there are uniformly distributed p-branes wrapping over the extra p-dimensions. We find that during cosmological evolution m-dimensional space expands with the exact power-law corresponding to pressureless matter while the extra p-dimensions contract. Adding matter, we also obtain solutions having the same property. We show that this might explain in a natural way why the extra dimensions are small compared to the observed three spatial directions.