Energy conditions in $f(Q,T)$ gravity

TL;DR

This paper investigates energy conditions in specific $f(Q,T)$ gravity models, demonstrating their compatibility with an accelerating universe and analyzing the implications of energy conditions on these models.

Contribution

It analyzes well-known $f(Q,T)$ models using recent observational data, highlighting their energy condition behaviors and accelerating universe compatibility.

Findings

Null, weak, and dominant energy conditions are satisfied.

Strong energy condition is violated, consistent with accelerated expansion.

Models support an equation of state parameter close to -1.

Abstract

The recently proposed $f(Q, T)$ gravity (Xu et al. Eur. Phys. J. C \textbf{79} (2019) 708) is an extension of the symmetric teleparallel gravity. The gravitational action $L$ is given by an arbitrary function $f$ of the non-metricity $Q$ and the trace of the matter-energy momentum tensor $T$. In this paper, we examined the essence of some well prompted forms of $f(Q,T)$ gravity models i.e. $f(Q,T)= mQ+bT$ and $f(Q,T)= m Q^{n+1}+b T$ where $m$, $b$, and $n$ are model parameters. We have used the proposed deceleration parameter, which predicts both decelerated and accelerated phases of the Universe, with the transition redshift by recent observations and obtains energy density ($\rho$) and pressure ($p$) to study the various energy conditions for cosmological models. The equation of state parameter ($\omega\simeq -1$) in the present model also supports the accelerating behavior of the Universe. In both, the models, the null, weak, and dominant energy conditions are obeyed with violating strong energy conditions as per the present accelerated expansion.