Square-Root parametrization of dark energy in f (Q) cosmology

Abstract

This paper is a parametrization of the equation of state (EoS) parameter of dark energy (DE), which is parameterized using Square-Root (SR) form i.e. ωSR=ω0+ω1zz2+1√, where ω0 and ω1 are free constants. This parametrization will be examined in the context of the recently suggested f(Q) gravity theory as an alternative to General Relativity (GR), in which gravitational effects are attributed to the non-metricity scalar Q with the functional form f(Q)=Q+αQn, where α and n are arbitrary constants. We derived observational constraints on model parameters using the Hubble dataset with 31 data points and the Supernovae (SNe) dataset from the Pantheon samples compilation dataset with 1048 data points. For the current model, the evolution of the deceleration parameter, density parameter, EoS for DE, and Om(z) diagnostic have all been investigated. It has been shown that the deceleration parameter favors the current accelerated expansion phase. It has also been shown that the EoS parameter for DE has a quintessence nature at this time.