Bouncing universe in Gauss-Bonnet gravity

TL;DR

This paper explores a bouncing cosmological model within Gauss-Bonnet gravity, demonstrating a non-singular universe where the equation of state crosses the phantom divide, indicating a viable bounce scenario.

Contribution

It introduces a specific hyperbolic scale factor in $f(R,G)$ gravity that satisfies bouncing criteria and avoids initial singularity, with detailed physical analysis.

Findings

The model achieves a non-singular bounce without initial singularity.

The equation of state crosses the phantom divide near the bounce.

All key features of a successful bouncing universe are satisfied.

Abstract

In this paper, a bouncing cosmological scenario is studied in the background of a flat FLRW model with a specific parametrized hyperbolic form of scale factor $ a $ in terms of $ t $, where $ \lambda $ is taken as the model parameter. This model is discussed in $ f(R,G) $ formalism having structured as $ f(R,G)=R+F(G) $, where $ R $ is Ricci scalar and $ G $ is the Gauss-Bonnet invariant. The proposed functional form of the Hubble parameter is considered in such a way that it satisfies the bouncing criteria of the model, which is free from the initial singularity. The physical consequences of the model are discussed. In this model, one can see that the EoS parameter crosses the quintom line $ \omega=-1 $ in the neighborhood of bouncing point $ t\approx0 $, which is a very strong criterion for a successful bouncing cosmological model. Finally, we find that all the essential features of the bouncing model are satisfied successfully.