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

TL;DR

This paper investigates a non-linear $f(Q,T)$ gravity cosmological model, constrains its parameters using observational data, and compares its predictions with the standard $ ext{Lambda}$CDM model through various diagnostics.

Contribution

It introduces a non-linear $f(Q,T)$ gravity model, constrains its parameters with observational data, and analyzes its properties using multiple diagnostic tools.

Findings

Model fits observational data well

Model passes through $ ext{Lambda}$CDM range in error plots

Energy conditions and diagnostics support model viability

Abstract

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. 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.