Holographic Dark Energy in Braneworld Models with a Gauss-Bonnet Term in the Bulk. Interacting Behavior and the w =-1 Crossing
Abstract
Description
We apply bulk holographic dark energy in general braneworld models with a Gauss-Bonnet term in the bulk and an induced gravity term and a perfect fluid on the brane. Without making any additional assumptions we extract the Friedmann equation on the physical brane and we show that a $ρ$-$ρ_Λ$ coupling arises naturally by the full 5D dynamics. The low-energy (late-time) evolution reveals that the effective 4D holographic dark energy behaves as ``quintom'', that is it crosses the phantom divide $w=-1$ during the evolution. In particular, the Gauss-Bonnet contribution decreases the present value of $w_Λ$, while it increases the growing rate of $w_Λ(z)$ with $z$, in comparison with the case where such a term is absent.
16 pages, version published in Phys. Lett. B
16 pages, version published in Phys. Lett. B