Dark energy constraint on equation of state parameter in the Weyl type $f(Q,T)$ gravity

TL;DR

This paper constrains the dark energy equation of state parameter within Weyl type $f(Q,T)$ gravity using observational data, revealing a transition from deceleration to acceleration and possible phantom behavior.

Contribution

It introduces a Bayesian analysis of the effective equation of state parameter in Weyl $f(Q,T)$ gravity using recent cosmic datasets, exploring its evolution and transition behaviors.

Findings

The equation of state parameter $oldsymbol{oldsymbol{ extit{ extbf{ extomega}}}}$ can be less than -1.

The universe transitions from deceleration to acceleration.

The analysis supports the possibility of phantom dark energy.

Abstract

The equation of state parameter is a significant method for characterizing dark energy models. We investigate the evolution of the equation of state parameter with redshift using a Bayesian analysis of recent observational datasets (the Cosmic Chronometer data (CC) and Pantheon samples). The Chevallier-Polarski-Linder parametrization of the effective equation of state parameter, $\omega_{eff}=\omega_0+\omega_a \left( \frac{z}{1+z}\right) $, where $\omega_0$ and $\omega_a$ are free constants, is confined to the Weyl type $f(Q,T)$ gravity, where $Q$ represents the non-metricity and $T$ is the trace of the energy-momentum tensor. We observe the evolution of the deceleration parameter $q$, the density parameter $\rho$, the pressure $p$, and the effective equation of state parameter $\omega$. The cosmic data limit for $\omega$ does not exclude the possibility of $\omega < -1$. It is seen that the parameter $\omega$ shows a transition from deceleration to acceleration, as well as a shift from $\omega>-1$ to $\omega<-1$.