An Extended Holographic Ricci Dark Energy Dominated Universe Under the Purview of Truncated Israel-Stewart Theory

This work demonstrates a viscous extended holographic Ricci dark energy (EHRDE) in a flat FRW universe based on the Israel-Stewart approach. Under the consideration that EHRDE dominates the universe, we study the evolution equation for the bulk viscous pressure i with the truncated form \(\tau \dot{i} + i=-3 \xi H \) , where \(\tau \) is the relaxation time, and \(\xi \) is the bulk viscosity coefficient. Considering the thermodynamic pressure of EHRDE and bulk viscous pressure, we demonstrate the evolution of the EoS parameter \(w_{DE}\) is behaving like a phantom i.e., \(w_{DE} \le -1\) . We also observe that \(p_{eff}=p+i\) is a monotone decreasing function of time. A decreasing effect of bulk viscosity happens with the evolution of the universe. Lastly, the generalized second law of thermodynamics is valid for the viscous EHRDE-dominated universe enveloped by an apparent horizon.