The cosmology in f(R,T) gravity without dark energy

TL;DR

This paper explores universe evolution in a modified gravity theory without dark energy, deriving relations between model functions and cosmic states, and fitting observational data with numerical simulations.

Contribution

It introduces a specific form of $f(R,T)$ gravity, analyzes all evolution modes for different equations of state, and demonstrates compatibility with astronomical observations.

Findings

Derived relations between $f(T)$ and equation of state $w$

Identified all possible evolution modes for different $w$ values

Achieved good fit with observational data through numerical simulations

Abstract

We examine the evolution of universe in $f(R,T)$ gravity where $R$ is the Ricci curvature and $T$ is the trace of energy momentum tensor. We focus on the specific form $f(R,T) = R+f(T)$ and explicitly find out the relation between $f(T)$ and state of equation $w$ by adiabatic condition. All possible modes of evolution of the scale factor for the five kinds of state of equation, $w= \pm 1, \pm 1/3, 0$ are exhibited. We simulate numerically the plots of redshift versus distance modulus for three interesting modes and then obtain the good fitting curve compared with the astronomical observation data.