Crossing w=-1 in Gauss-Bonnet Brane World with Induced Gravity

TL;DR

This paper demonstrates that in a Gauss-Bonnet brane world with induced gravity, the crossing of the dark energy equation of state parameter w=-1 can occur naturally without phantom fields, influenced by bulk parameters.

Contribution

It shows a novel mechanism for w=-1 crossing in brane cosmology models with Gauss-Bonnet terms, avoiding phantom energy.

Findings

w(z) crossing -1 achieved without phantom fields

Gauss-Bonnet term influences dark energy behavior

Bulk parameters are crucial for crossing phenomenon

Abstract

Recent type Ia supernovas data seemingly favor a dark energy model whose equation of state $w(z)$ crosses -1 very recently, which is a much more amazing problem than the acceleration of the universe. In this paper we show that it is possible to realize such a crossing without introducing any phantom component in a Gauss-Bonnet brane world with induced gravity, where a four dimensional curvature scalar on the brane and a five dimensional Gauss-Bonnet term in the bulk are present. In this realization, the Gauss-Bonnet term and the mass parameter in the bulk play a crucial role.