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

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.