Constrained cosmological model in f(Q, T) gravity with non-linear non-metricity

The f(Q, T) cosmological model has emerged as a promising framework for understanding various aspects of cosmic evolution. In this study, we focused on obtaining the constraints of the free parameters in the non-linear form of non-metricity in f(Q, T) gravity using the Hubble, Pantheon, and BAO datasets. To determine the best -fit values for the model parameters and the equation of state (EoS) parameter, we employed an MCMC analysis and obtained omega = -1.03, omega = -1.02 and omega = -1.02 respectively for CC, SNIa and CC+SNIa+BAO datasets. By examining the error bar plots, we observed that both the model curve and the Lambda CDM curve successfully passed through the range obtained from the datasets. Additionally, we studied the state finder diagnostics and energy conditions to gain insights into the properties of the model. Furthermore, we conducted an analysis using the Om(z) diagnostic, which provides a null test for the validity of the Lambda CDM model. Also the current age of the Universe has been obtained for CC, SNIa and CC+SNIa+BAO datasets respectively as, t(0) = 14.05 Gyrs, t(0) = 13.48 Gyrs and t(0) = 13.56 Gyrs.