Dark energy and decompactification in string gas cosmology

TL;DR

This paper investigates how string gas cosmology influences the stability and dynamics of extra dimensions, revealing that baryons and strings can induce acceleration without vacuum energy, challenging traditional cosmological models.

Contribution

It demonstrates that baryons and string gases can cause acceleration in visible dimensions without requiring vacuum energy, offering new insights into late-time cosmological behavior.

Findings

Baryons lead to decompactification of extra dimensions.

String gas can stabilize extra dimensions against baryon effects.

Acceleration can occur without vacuum energy due to baryon-string interplay.

Abstract

We study the stability of extra dimensions in string gas cosmology at late times. Vacuum energy and, interestingly, baryons lead to decompactification after they become dynamically important. The string gas can stabilise the effect of baryons, but not that of vacuum energy. However, we find that the interplay of baryons and strings can lead to acceleration in the visible dimensions, without the need for vacuum energy.