Exploring accelerated expansion in the universe: A study of $f(Q,T)$ gravity with parameterized EoS and cosmological constraints

Abstract

The study conducted in this research paper utilizes the $f(Q,T)$ gravity, where $Q$ represents non-metricity and $T$ represents the trace of the energy-momentum tensor, to investigate the accelerated expansion of the universe. To complete the study, an effective EoS with one parameter $\hat{I}\pm$, is parameterized as $\ddot{I}{‰}_{eff}=-\frac{3}{\hat{I}\pm (1+z{)}^3+3}$. The linear version of $f(Q,T)=-Q+\ddot{I}ƒT$ is also considered, where $\ddot{I}ƒ$ is a constant. By constraining the model with six BAO points, 57 Hubble points, and 1048 Pantheon sample datasets, the parameters $\hat{I}\pm$ and $\ddot{I}ƒ$ are determined to best match the data. The cosmological parameters and energy conditions for the model are derived and examined. The results show that the model is in good agreement with observations, and can serve as a valuable starting point for analyzing FLRW models in the $f(Q,T)$ theory of gravity.

Chinese Journal of Physics accepted version