Dark energy nature of viscus universe in f(Q)-gravity with observational constraints
Anirudh Pradhan, Dinesh Chandra Maurya, Archana Dixit
Abstract
In this study, we have investigated the dark energy behavior of the viscus-fluid in [Formula: see text]-gravity in a flat, isotropic and homogeneous Friedmann–Lemaitre–Robertson–Walker (FLRW) space-time metric. We have considered the linear form of [Formula: see text] function as [Formula: see text] with [Formula: see text] and [Formula: see text] as model parameters. We have solved the field equations for the scale factor [Formula: see text] and found [Formula: see text], where [Formula: see text] and [Formula: see text] and [Formula: see text] is an integrating constant, [Formula: see text] is the EoS for normal matter and [Formula: see text] is generated from bulk-viscus fluid. We have calculated the several cosmological parameters for this scale factor and studied their physical and geometrical behavior along the observational data sets [Formula: see text] and Union [Formula: see text] compilation of SNe Ia data sets. We have observed that the [Formula: see text] factor reveals the presence of cosmological constant and for [Formula: see text], the acceleration drives by the bulk-viscosity of the fluid and it behaves just like dark energy model without cosmological constant. We have studied the effective EoS [Formula: see text] and found [Formula: see text]. We have evaluated the age of the present universe as [Formula: see text] Gyrs. and also, we have studied the nature of deceleration parameter with the signature-flipping point at [Formula: see text] and the present value of deceleration parameter [Formula: see text] is obtained as [Formula: see text].