The $f(Q, T)$ gravity and affine EoS: observational aspects

TL;DR

This study explores cosmic expansion in $f(Q,T)$ gravity with an affine EoS, constraining model parameters using observational data and analyzing the universe's evolution and age.

Contribution

It introduces a linear $f(Q,T)$ gravity model with affine EoS and constrains it using multiple observational datasets, providing insights into cosmic evolution.

Findings

Model parameters constrained within $1\sigma$ of Planck results.

Cosmographic parameters analyzed to understand universe evolution.

Determined universe's age consistent with Planck data.

Abstract

In this paper, we investigate the cosmic expansion scenarios within the framework of $f(Q,T)$ gravity by using the affine equation of state (EoS) parameter. Specifically, we consider the linear form $f(Q,T)=Q+\beta T$, where $\beta$ is a free model parameter. We use Bayesian statistical methods, specifically the $\chi^2$ minimization technique to constrain the model parameters using Cosmic Chronometer (CC), Pantheon+SH0ES and DESI BAO data. We further analyze the characteristics of the derived cosmological model. A comprehensive study of energy density, pressure, equation of state parameter and cosmographic parameters are carried out to understand the evolution of the Universe in this model. The determination of present age of the universe for this model is within $1\sigma$ with Planck results.