Cosmology from an exponential dependence on the trace of the energy-momentum tensor -- Numerical approach and cosmological tests

TL;DR

This paper explores a new exponential $f(R,T)$ gravity model using numerical methods and scalar field coupling, demonstrating its potential to describe accelerated cosmic expansion consistent with observational data.

Contribution

It introduces an exponential dependence on the trace of the energy-momentum tensor in $f(R,T)$ gravity and analyzes its cosmological implications with numerical and analytical approaches.

Findings

The model fits cosmological data well.

The scalar field coupling supports accelerated expansion.

Analytical parameters align with numerical results.

Abstract

In this paper, we present the cosmological scenario obtained from $f(R,T)$ gravity by using an exponential dependence on the trace of the energy-momentum tensor. With a numerical approach applied to the equations of motion, we show several precise fits and the respective cosmological consequences. As a matter of completeness, we also analyzed cosmological scenarios where this new version of $f(R,T)$ is coupled with a real scalar field. In order to find analytical cosmological parameters, we used a slow-roll approximation for the evolution of the scalar field. This approximation allowed us to derived the Hubble and the deceleration parameters whose time evolutions describe the actual phase of accelerated expansion, and corroborate with our numerical investigations. Therefore, the analytical parameters unveil the viability of this proposal for $f(R,T)$ in the presence of an inflaton field.