FRW Universe with a Parameterization of the EoS Parameter in f(Q) Gravity

Abstract

In the field of theoretical physics, the fundamental characteristics and evolutionary mechanism of dark energy remain a subject of ongoing enquiry. While the simplest explanation for dark energy within General Relativity Theory is the cosmological constant, this concept faces a significant challenge known as the fine-tuning problem. In this study, we adopt an alternative approach, where we attribute the evolution of dark energy to the gravitational sector rather than the matter source. We explore the recently proposed theory of gravity known as modified symmetric teleparallel gravity, [Formula: see text], in which gravitational interactions are governed by the non-metricity term Q. Within this manuscript, we consider [Formula: see text] that incorporates nonlinear forms of the non-metricity scalar, where [Formula: see text] and [Formula: see text] are free model parameters. Subsequently, we determine the values of these model parameters that align with the observed values of cosmographic parameters. Our analysis delves into the behavior of various cosmological parameters, including the deceleration parameter, density, and equation of state parameters, as well as the cosmological distances for our cosmological model.