Cosmic acceleration and crossing of $\omega=-1$ in non-minimal modified Gauss-Bonnet gravity

TL;DR

This paper explores how non-minimal coupling of scalar fields and potentials with modified Gauss-Bonnet gravity can explain cosmic acceleration and allow the dark energy equation of state to cross the phantom divide.

Contribution

It generalizes previous models by including scalar potentials and investigates conditions for crossing =-1 in non-minimally coupled $f(G)$ gravity with tachyonic matter.

Findings

Conditions for =-1 crossing derived

Scalar potential inclusion enhances model flexibility

Cosmic acceleration explained without dark energy

Abstract

Modified Gauss-Bonnet, i.e, $f(G)$ gravity is a possible explanation of dark energy. Late time cosmology for the $f(G)$ gravity non-minimally coupled with a free massless scalar field have been investigated in Ref. [32]. In this paper we generalize the work of Ref. [32] by including scalar potential in the matter Lagrangian which is non-minimally coupled with modified Gauss-Bonnet gravity. Also we obtain the conditions for having a much more amazing problem than the acceleration of the universe, i.e: crossing of $\omega=-1$, in $f(G)$ non-minimally coupled with tachyonic Lagrangian.