Quintessence-like features in the late-time cosmological evolution of $f(Q)$ symmetric teleparallel gravity

TL;DR

This paper explores late-time cosmological evolution within $f(Q)$ gravity, showing it can explain cosmic acceleration without dark energy through a parametrized Hubble approach and observational data fitting.

Contribution

It provides an exact solution in $f(Q)$ gravity and constrains model parameters using multiple datasets, highlighting late-time acceleration without dark energy.

Findings

Deceleration parameter changes sign with redshift

Cosmological parameters evolve consistently with observations

Late-time acceleration explained without dark energy

Abstract

In this study, we investigate the cosmological history within the framework of modified $f(Q)$ gravity, which proposes an alternative theory of gravity where the gravitational force is described by a non-metricity scalar. By employing a parametrization scheme for the Hubble parameter, we obtain the exact solution to the field equations in $f(Q)$ cosmology. To constrain our model, we utilize external datasets, including 57 data points from the Hubble dataset, 1048 data points from the SN dataset, and six data points from the BAO dataset. This enables us to determine the best-fit values for the model parameters involved in the parameterization scheme. We analyze the cosmic evolution of various cosmological parameters, including the deceleration parameter, which exhibits the expected behavior in late-time cosmology and changes its signature with redshift. Further, we present the evolution of energy density, EoS parameter, and other geometrical parameters with respect to redshift. Furthermore, we discuss several cosmological tests and diagnostic analyses. Our findings demonstrate that the late-time cosmic evolution can be adequately described without the need for dark energy by employing a parametrization scheme in modified gravity.