Modified $f(R,G,T)$ Gravity in the Quintom model, and Inflation

TL;DR

This paper explores a modified gravity model involving functions of curvature, Gauss-Bonnet invariant, and stress-energy trace, coupled with scalar fields, to analyze conditions for cosmic bounce and inflation without crossing the phantom divide.

Contribution

It introduces a general $f(R,G,T)$ gravity model with scalar fields, analyzing bounce conditions, energy conservation, and inflationary behavior, encompassing various specific models.

Findings

Successful bounce conditions are identified.

The EoS parameter cannot cross the phantom divide with only inflaton.

The model aligns with Planck 2018 observations.

Abstract

In this paper, I consider a $f(R, G, T)$ modified gravity model where $R$ represents the Ricci scalar, $G$ denotes the Gauss-Bonnet invariant, and $T$ signifies the trace of the stress-energy tensor. This model is coupled with two distinct types of scalar fields. In the flat Friedmann-Lema\^{\i}tre-Robertson-Walker (FLRW) universe, the necessary conditions for a successful bounce are achieved. Under these circumstances, it is demonstrated that the equation of state (EoS) parameter cannot cross the phantom divider when only the inflaton scalar field is considered. Appropriate conditions to preserve the conservation of energy law are obtained. The absence of radiation domination is confirmed by referencing one of the collections of the Planck 2018 report. Moreover, it has been demonstrated that this is a general model, encompassing other models such as Weyl conformal geometry and the inflation epoch. Numerical calculations and graphs are used to confirm the results.