Cosmological constraints on dark energy in $f(Q)$ gravity: A parametrized perspective

TL;DR

This paper investigates a modified gravity model called $f(Q)$ gravity, parametrizes the effective equation of state, and uses observational data to constrain the model, confirming the universe's accelerated expansion and stability.

Contribution

It introduces a specific $f(Q)$ power-law model with parametrized EoS and constrains it using multiple observational datasets, providing new insights into cosmic acceleration within $f(Q)$ gravity.

Findings

Current deceleration parameter $q_0$ indicates acceleration.

Model fits observational data well.

Stability analysis confirms the model's robustness.

Abstract

In this paper, we focus on the parametrization of the effective equation of state (EoS) parameter within the framework of $f(Q)$ symmetric teleparallel gravity. Here, the gravitational action is represented by an arbitrary function of the non-metricity scalar $Q$. By utilizing a specific parametrization of the effective EoS parameter and a power-law model of $f(Q)$ theory, namely $f(Q)=\beta Q^{\left( m+1\right) }$ (where $\beta$ and $m$ are arbitrary constants), we derive the cosmological solution of the Hubble parameter $H(z)$. To constrain model parameters, we employ recent observational data, including the Observational Hubble parameter Data ($OHD$), Baryon Acoustic Oscillations data ($BAO$), and Type Ia supernovae data ($SNe$ Ia). The current constrained value of the deceleration parameter is found to be $q_{0}=-0.50^{+0.01}_{-0.01}$, indicating that the current Universe is accelerating. Furthermore, we examine the evolution of the density, EoS, and $Om(z)$ diagnostic parameters to deduce the accelerating nature of the Universe. Finally, we perform a stability analysis with linear perturbations to confirm the model's stability.