Interaction of divergence-free deceleration parameter in Weyl-type $f(Q,T)$ gravity

TL;DR

This paper investigates a Weyl-type $f(Q,T)$ gravity model with a divergence-free deceleration parameter, deriving cosmological solutions and constraining parameters using observational data to explore universe acceleration.

Contribution

It introduces a divergence-free parametrization of the deceleration parameter within Weyl-type $f(Q,T)$ gravity and tests its consistency with observational data.

Findings

Model predicts an accelerating universe with current deceleration parameter $q_0$.

Transition redshift $z_t$ aligns with observational constraints.

Divergence-free parametrization is consistent with Weyl-type $f(Q,T)$ gravity.

Abstract

We study an extension of symmetric teleparallel gravity i.e. Weyl-type $f(Q,T)$ gravity and the divergence-free parametrization of the deceleration parameter $q(z) = q_{0}+q_{1}\frac{z(1+z)}{1+z^2}$ ($q_{0}$ and $q_{1}$ are free constants) to explore the evolution of the universe. By considering the above parametric form of $q$, we derive the Hubble solution and further impose it in the Friedmann equations of Weyl-type $f(Q, T)$ gravity. To see whether this model can challenge the $\Lambda$CDM limits, we computed the constraints on the model parameters using the Bayesian analysis for the Observational Hubble data ($OHD$) and the Pantheon sample ($SNe\,Ia$). Furthermore, the deceleration parameter depicts the accelerating behavior of the universe with the present value $q_0$ and the transition redshift $z_t$ (at which the expansion transits from deceleration to acceleration) with $1-\sigma$ and $2-\sigma$ confidence level. We also examine the evolution of the energy density, pressure, and effective equation of state parameters. Finally, we demonstrate that the divergence-free parametric form of the deceleration parameter is consistent with the Weyl-type $f(Q,T)$ gravity.