Modified GBIG Scenario as an Alternative for Dark Energy

TL;DR

This paper proposes a modified DGP-inspired braneworld model incorporating $f(R)$ gravity and Gauss-Bonnet terms, which can explain cosmic acceleration and phantom-like behavior without dark energy or phantom fields.

Contribution

It introduces a novel combination of $f(R)$ gravity and Gauss-Bonnet effects in a DGP framework, providing a new alternative explanation for dark energy.

Findings

Realizes phantom-like behavior without phantom fields

Effective equation of state crosses the cosmological constant line

Aligns with observational data on cosmic acceleration

Abstract

We construct a DGP-inspired braneworld model where induced gravity on the brane is modified in the spirit of $f(R)$ gravity and stringy effects are taken into account by incorporation of the Gauss-Bonnet term in the bulk action. We explore cosmological dynamics of this model and we show that this scenario is a successful alternative for dark energy proposal. Interestingly, it realizes the phantom-like behavior without introduction of any phantom field on the brane and the effective equation of state parameter crosses the cosmological constant line naturally in the same way as observational data suggest.