Brane Universes with Gauss-Bonnet-Induced-Gravity

TL;DR

This paper explores generalized brane world cosmologies with Gauss-Bonnet and induced gravity effects, analyzing their early and late universe behavior, including the possibility of late-time phantom acceleration.

Contribution

It extends previous GBIG models by incorporating bulk cosmological constant and brane tension, revealing new late-time acceleration behaviors.

Findings

Some models exhibit late-time phantom acceleration.

Inclusion of bulk cosmological constant allows for richer cosmological dynamics.

Models can start with a finite density Big Bang.

Abstract

The DGP brane world model allows us to get the observed late time acceleration via modified gravity, without the need for a ``dark energy'' field. This can then be generalised by the inclusion of high energy terms, in the form of a Gauss-Bonnet bulk. This is the basis of the Gauss-Bonnet-Induced-Gravity (GBIG) model explored here with both early and late time modifications to the cosmological evolution. Recently the simplest GBIG models (Minkowski bulk and no brane tension) have been analysed. Two of the three possible branches in these models start with a finite density ``Big-Bang'' and with late time acceleration. Here we present a comprehensive analysis of more general models where we include a bulk cosmological constant and brane tension. We show that by including these factors it is possible to have late time phantom behaviour.