Phantom-like effects in asymmetric brane embedding with induced gravity and the Gauss-Bonnet term in the Bulk

TL;DR

This paper explores how asymmetric brane models with induced gravity and Gauss-Bonnet terms can exhibit phantom-like cosmic acceleration without exotic fields, analyzing effects of symmetry and curvature on this behavior.

Contribution

It introduces a new asymmetric brane model incorporating Gauss-Bonnet effects and analyzes conditions for phantom-like behavior without phantom fields.

Findings

Phantom-like behavior occurs at smaller redshifts in asymmetric models without Gauss-Bonnet.

In models with curvature effects, phantom-like behavior appears in both symmetric and asymmetric solutions.

Phantom-like acceleration is achieved without introducing phantom fields on the brane or in the bulk.

Abstract

We construct an asymmetric braneworld embedding with induced gravity on the brane, where stringy effects are taken into account by incorporation of the Gauss-Bonnet term in the bulk action. We derive the effective Friedmann equation of the brane and then we investigate the possible realization of the phantom-like behavior in this setup. We show that in the absence of the Gauss-Bonnet term in the bulk action (a pure induced gravity scenario), the phantom-like behavior in asymmetric case can be realized in smaller redshift than the corresponding symmetric case. We show also that in the general case with curvature effect, the phantom-like behavior can be realized in two subcases: in a symmetric subcase and also in an asymmetric branch of the solutions. In either cases this phantom-like behavior happens without introducing any phantom fields neither on the brane nor in the bulk.