Non-conventional cosmology from a brane-universe

TL;DR

This paper explores how brane-universes, with matter confined to a 4D hypersurface and gravity in an extra dimension, exhibit distinct cosmological behaviors from standard models, providing new solutions and discussing implications.

Contribution

It introduces a new class of exact solutions for brane-universes with a constant extra dimension radius and evolving brane, highlighting differences from standard cosmology.

Findings

Brane-universes differ fundamentally from standard cosmology.

New exact solutions with a static extra dimension and dynamic brane.

Discussion of various cosmological consequences.

Abstract

We consider ``brane-universes'', where matter is confined to four-dimensional hypersurfaces (three-branes) whereas one extra compact dimension is felt by gravity only. We show that the cosmology of such branes is definitely different from standard cosmology and identify the reasons behind this difference. We give a new class of exact solutions with a constant five-dimensional radius and cosmologically evolving brane. We discuss various consequences.