On Bouncing Brane-Worlds, S-branes and Branonium Cosmology

TL;DR

This paper explores higher-dimensional brane-world models where the induced 4D universe experiences a bounce, analyzing their geometric features, stability, and potential for stable bouncing cosmologies.

Contribution

It introduces new classes of bouncing brane-world solutions involving S-branes and D-brane systems, with insights into their stability and geometric properties.

Findings

Certain models exhibit positive acceleration without event horizons.

Some solutions are stable from the bulk perspective.

Bouncing cosmologies can arise without violating all energy conditions.

Abstract

We present several higher-dimensional spacetimes for which observers living on 3-branes experience an induced metric which bounces. The classes of examples include boundary branes on generalised S-brane backgrounds and probe branes in D-brane/anti D-brane systems. The bounces we consider normally would be expected to require an energy density which violates the weak energy condition, and for our co-dimension one examples this is attributable to bulk curvature terms in the effective Friedmann equation. We examine the features of the acceleration which provides the bounce, including in some cases the existence of positive acceleration without event horizons, and we give a geometrical interpretation for it. We discuss the stability of the solutions from the point of view of both the brane and the bulk. Some of our examples appear to be stable from the bulk point of view, suggesting the possible existence of stable bouncing cosmologies within the brane-world framework.