Observational constraints on viscous Ricci dark energy model

Abstract

In this paper, Ricci dark energy (RDE) model with bulk viscosity is studied to observe the cosmic accelerating expansion phenomena. It is thought that the negative pressure caused by bulk viscosity can play the role of a dark energy component. We assume that the total bulk viscosity coefficient is proportional to the velocity and acceleration of the expansion of the universe in the form, $\xi =\xi _{0}+\xi _{1}h+\xi _{2}h ^{\prime } $ where $\xi _{0}$ , $\xi _{1}$ and $\xi _{2}$ are the constants and $h = {H}/{H_{0}}$ , the dimensionless Hubble’s parameter. We give out the exact solutions of such model. We show that the model corresponds to early deceleration and then a smooth transition into an accelerated epoch. We analyze the model with statefinder and $Om$ diagnostics and find that the model is different from standard $\varLambda CDM$ model at present but approaches to $\varLambda CDM$ as $t\rightarrow \infty $ . We constrain the model using latest observational data namely Ia Supernovae data (SN Ia), observed Hubble parameter dataset (OHD) and baryon acoustic oscillations (BAO) measurement to evaluate the best estimated values of all bulk viscous parameters. It is claimed that the non-viscous RDE model suffers the age problem. However, we find that viscous RDE alleviates the age problem. The viscous Ricci dark energy model is compatible to explain the present accelerated expansion of the universe.