Analytic Solutions and Observational support: A study of $f(R,T)$ gravity with $f(R,T)=R+h(T)$

TL;DR

This paper explores exact cosmological solutions in $f(R,T)$ gravity with a perfect fluid, demonstrating models that describe universe evolution from matter dominance to acceleration, supported by observational data.

Contribution

It provides analytic solutions in $f(R,T)$ gravity, analyzes their physical implications, and establishes equivalence with modified Chaplygin gas, advancing understanding of cosmic evolution in this framework.

Findings

Two types of universe models depending on constant sign: finite and ever-expanding.

Model supports universe evolution from matter dominance to acceleration.

Observational data favor the model's validity for cosmic evolution.

Abstract

The present work deals with cosmological solutions in $f(R,T)$ gravity theory for perfect fluid with constant equation of state ($\omega$). For a viable cosmological solution $\omega$ is restricted to $\omega<\dfrac{1}{3}$. Also depending on the sign of an arbitrary constant one has two possible solutions: a finite universe model and an ever expanding model of the universe. Field theoretic description of the model and possibility of a ghost scalar field has been studied. Also, an equivalence with modified Chaplygin gas has been shown. Finally, from the observational data it has been concluded that this model represents an evolution of the universe from matter dominated phase to present accelerating phase.