Logarithmic and Strong Coupling Models in Weyl-Type $f(Q,T)$ Gravity

TL;DR

This study investigates Weyl-type $f(Q,T)$ gravity models with logarithmic and strong coupling functions, analyzing their cosmological implications and fitting them to observational data to describe universe acceleration.

Contribution

It introduces and constrains two novel $f(Q,T)$ gravity models with logarithmic and strong coupling forms using observational data and numerical solutions.

Findings

Models describe transition from deceleration to acceleration.

Models exhibit quintessence-like behavior and approach $\\Lambda$CDM at late times.

Calculated universe age aligns with Planck and stellar data.

Abstract

In this paper, we have explored the cosmological implications of Weyl-type $f(Q,T)$ gravity, a modified gravitational theory formulated from Weyl geometry. The nonmetricity scalar $Q$ is coupled to the trace $T$ of the energy-momentum tensor. We analyze two models based on the logarithmic and strong coupling form of the function $f(Q,T)$. The corresponding field equations are then solved numerically after reformulating the system in terms of redshift. We used combined dataset from Cosmic Chronometers (CC), Pantheon$^+$ supernovae, and Baryon Acoustic Oscillations (BAO) and performed the Markov Chain Monte Carlo (MCMC) analysis to constrain the model parameters. Using the constrained parameters, the geometrical and dynamical aspects of the models are analyzed. The results successfully describe a transition from decelerated to accelerated expansion for both the models. The models mostly exhibit quintessence-like behavior and asymptotically approach the $\Lambda$CDM scenario at late times. The calculated age of the Universe from each model aligns with constraints from Planck and stellar age data. The violation of the strong energy condition and the satisfaction of null energy condition and dominant energy conditions are shown.