Cosmological acceleration from a gas of strings

TL;DR

This paper explores how a string gas in cosmology can cause the universe's accelerated expansion through oscillations of extra dimensions, fitting observations without a cosmological constant.

Contribution

It demonstrates that string gas cosmology can naturally produce accelerated expansion via oscillations of extra dimensions, offering an alternative to dark energy models.

Findings

Oscillations of extra dimensions induce acceleration in visible dimensions.

The model fits observed accelerated expansion without a cosmological constant.

String gas cosmology provides a viable alternative explanation for cosmic acceleration.

Abstract

In string gas cosmology, the extra dimensions of the underlying theory are kept at a microscopic scale by a gas of strings. In the matter-dominated era, however, dust pressure can lead to oscillations of the extra dimensions and to acceleration in the three visible dimensions, even with a vanishing cosmological term. We review the resulting oscillating expansion history, that provides an acceptable fit to the observed accelerated expansion of the Universe.