Quintessence dark energy model in non-linear $f(Q)$ theory with bulk-viscosity

TL;DR

This paper explores a non-linear $f(Q)$ gravity model with bulk viscosity in an LRS Bianchi type-I universe, constraining it with observational data and analyzing its cosmological implications including acceleration and age.

Contribution

It introduces a new $f(Q)$ gravity model with bulk viscosity, solves the field equations, and constrains the model using observational data to study cosmic evolution.

Findings

The universe's age is approximately 13.8 billion years.

The model predicts a quintessential, ever-accelerating universe.

Cosmological parameters align with observational constraints.

Abstract

In this study, we investigate a locally rotationally symmetric (LRS) Bianchi type-I cosmological model in non-linear form of $f(Q)$ gravity with observational constraints. We solved the modified Einstein's field equations with a viscous fluid source and got a hyperbolic solution. First, we apply MCMC analysis to the cosmic chronometer (CC), Baryon Acoustic Oscillation (BAO) and Pantheon datasets to place observational constraints on the model parameters. Using constrained values of model parameters, we study the behavior of cosmological parameters, such as the Hubble parameter $H$, the deceleration parameter $q$, and the equation of state (EoS) parameter $\omega_{v}$ with the skewness parameter $\delta_{v}$ for the viscous fluid. In addition, we perform the Om diagnostics and statefinder analysis to categorize dark energy models. Also, we studied cosmographic series coefficients to explore the whole evolution of the derived universe model. We estimated the current age of the universe as $t_{0}\approx13.8$ Gyrs. We obtained a quintessential and ever-accelerating model with bulk viscosity fluid.