Cosmological Dynamics on a Novel $f(Q)$ Gravity Model with Recent DESI DR2 Observation

TL;DR

This paper explores a new $f(Q)$ gravity model's ability to explain cosmic acceleration, constrained by recent observational data, and finds it successfully describes the transition from deceleration to acceleration.

Contribution

The study introduces a novel $f(Q)$ gravity model and provides observational constraints using recent datasets, analyzing its physical behavior and cosmological implications.

Findings

Model fits observational data well with best-fit parameters.

The universe transitions from deceleration to acceleration at redshift z=0.573.

The model's equation of state indicates quintessence-like behavior.

Abstract

In this article, we investigate the cosmological viability of a modified symmetric teleparallel gravity model within the $f(Q)$ framework. We derive observational constraints on the model parameters by performing a Markov Chain Monte Carlo analysis using a combined dataset consisting of cosmic chronometers, PantheonPlus SH0ES, and DESI BAO DR2. Our analysis yields the best-fit values for the model parameters $m=-0.386 \pm 0.090$ and $n=-1.055 \pm 0.047$, along with the cosmological parameters at present: $H_0 = 73.19 \pm 0.25$, $q_0 = -0.51 \pm 0.6$, and $\omega_{0} = -0.73 \pm 0.3$, at 68\% CL. Furthermore, we examine the physical behavior of the model, focusing on the effective equation of state and deceleration parameter. Our findings indicate that the model experiences a transition from the early deceleration phase to the late-time cosmic acceleration, and the transition occurs at a redshift $z_{tr} = 0.573$. We also analyse the $om(z)$ diagnostic, which reflects a positive slope, supporting the behavior of the equation of state parameter in the quintessence region.