Constraining effective equation of state in $f(Q,T)$ gravity

TL;DR

This paper investigates the $f(Q,T)$ gravity theory using observational data to constrain its parameters, demonstrating its consistency with cosmic acceleration and dark energy phenomena.

Contribution

It introduces a parameterized effective equation of state within $f(Q,T)$ gravity and constrains it using Pantheon supernova data, highlighting its potential to explain the Universe's accelerated expansion.

Findings

Model fits observational data well

Parameters $b$, $m$, and $n$ are tightly constrained

Supports $f(Q,T)$ as a viable gravity theory for dark energy

Abstract

New high-precision observations are now possible to constrain different gravity theories. To examine the accelerated expansion of the Universe, we used the newly proposed $f(Q,T)$ gravity, where $Q$ is the non-metricity, and $T$ is the trace of the energy-momentum tensor. The investigation is carried out using a parameterized effective equation of state with two parameters, $m$ and $n$. We have also considered the linear form of $f(Q,T)= Q+bT$, where $b$ is constant. By constraining the model with the recently published 1048 Pantheon sample, we were able to find the best fitting values for the parameters $b$, $m$, and $n$. The model appears to be in good agreement with the observations. Finally, we analyzed the behavior of the deceleration parameter and equation of state parameter. The results support the feasibility of $f(Q,T)$ as a promising theory of gravity, illuminating a new direction towards explaining the Universe's dark sector.