Cosmology on a Brane in Minkowski Bulk

TL;DR

This paper explores the cosmology of a 3-brane in a 5D Minkowski bulk with an intrinsic curvature term, revealing solutions that resemble standard cosmology and exhibit late-time acceleration.

Contribution

It derives brane-Friedmann equations with an intrinsic curvature term and analyzes solution regimes, including transitions to 5D behavior or self-inflation.

Findings

Existence of two solution classes near standard cosmology

Transition to 5D regime or self-inflation at large Hubble radius

Comparison with perturbative approaches and brane embedding analysis

Abstract

We discuss the cosmology of a 3-brane embedded in a 5D bulk space-time with a cosmological constant when an intrinsic curvature Ricci scalar is included in the brane action. After deriving the `brane-Friedmann' equations for a Z_2 symmetrical metric, we focus on the case of a Minkowski bulk. We show that there exist two classes of solutions, close to the usual Friedmann-Lemaitre-Robertson-Walker cosmology for small enough Hubble radii. When the Hubble radius gets larger one either has a transition to a fully 5D regime or to a self-inflationary solution which produces a late accelerated expansion. We also compare our results with a perturbative approach and eventually discuss the embedding of the brane into the Minkowski space-time. This latter part of our discussion also applies when no intrinsic curvature term is included.