Cosmological Evolution in f(R,T) theory with Collisional Matter

TL;DR

This paper investigates how collisional matter influences the evolution of cosmological parameters within f(R,T) gravity, comparing models with observational data and non-collisional matter.

Contribution

It introduces a numerical analysis of cosmological evolution in f(R,T) gravity including collisional matter, extending previous models to incorporate self-interacting matter effects.

Findings

Models with collisional matter are consistent with observational data.

The evolution of the effective equation of state aligns with ΛCDM predictions.

Collisional matter impacts the deceleration parameter evolution.

Abstract

We study the evolution of the cosmological parameters, namely, the deceleration parameter $q(z)$ and the parameter of effective equation of state in a universe contains, besides the ordinary matter and dark energy, a self-interacting (collisional matter), in the generalized $f(R,T)$ theory of gravity, where $R$ and $T$ are the curvature scalar and the trace of the energy-momentum tensor, respectively. We use the generalized FRW equations the equation of continuity and obtain a differential equation of second order in $H(z)$, and solve it numerically for studying the evolution of the cosmological parameters. Two $f(R,T)$ models are considered and the results with collisional matter are compared with the ones of the $\Lambda$CDM model, and also with the model where there exists only non-collisional matter. The curves show that the models are acceptable because the values found for $w_{eff}$ are consistent with the observational data.