Testing some f(R,T) gravity models from energy conditions

TL;DR

This paper investigates specific $f(R,T)$ gravity models, demonstrating that with suitable parameters, energy conditions are met and certain cosmological solutions like de Sitter and power-law can be stable.

Contribution

It introduces particular functional forms of $f(T)$ in $f(R,T)$ gravity and analyzes their energy conditions and stability of cosmological solutions.

Findings

Energy conditions can be satisfied with parameter tuning.

De Sitter and power-law solutions can be stable under certain conditions.

Models exhibit viable cosmological behaviors with appropriate parameters.

Abstract

We consider $f(R, T)$ theory of gravity, where $R$ is the curvature scalar and $T$ the trace of the energy momentum tensor. Attention is attached to the special case, $f(R, T)= R+2f(T)$ and two expressions are assumed for the function $f(T)$, $\frac{a_1T^n+b_1}{a_2T^n+b_2}$ and $a_3\ln^{q}{(b_3T^m)}$, where $a_1$, $a_2$, $b_1$, $b_2$, $n$, $a_3$, $b_3$, $q$ and $m$ are input parameters. We observe that by adjusting suitably these input parameters, energy conditions can be satisfied. Moreover, an analyse of the perturbations and stabilities of de Sitter solutions and power-law solutions is performed with the use of the two models. The results show that for some values of the input parameters, for which energy conditions are satisfied, de Sitter solutions and power-law solutions may be stables.