Tracing cosmic evolution through Weyl-Type f(Q,T) gravity model: Theoretical analysis and observational validation

Abstract

We investigate the cosmic evolution of the Universe across different cosmological epochs in exponential Weyl-type $f(Q,T)$ gravity model. The theoretical analysis involves a detailed dynamical system approach, where we define dimensionless variables and derive a system of linear differential equations to identify critical points corresponding to the radiation, matter and de Sitter phase. The findings show the transition from deceleration to acceleration phase, with stable and unstable critical points characterizing different phases of the evolution. In the second phase, we validate the theoretical predictions by using observational data from Cosmic Chronometers ($CC$) and Pantheon${}^{+}$ datasets. We constrain the Hubble parameter and subsequently analyzed the other cosmological and geometrical parameters. In this approach also, the transition from deceleration to acceleration has been confirmed, with the equation of state (EoS) parameter approaching $\Lambda$CDM at late times. The model behavior in both the approaches show the late-time behavior of the Universe. The evolutionary behavior of both the Hubble parameter and distance modulus, reinforcing the reliability of the Weyl-type $f(Q,T)$ gravity model in describing the expansion history of Universe.