Viscous cosmology in holographic dark energy with Granda–Oliveros cut-off

We study the effect of bulk viscosity on holographic dark energy(HDE) with Granda–Oliveros infra-red cut-off. We focus on a generalized form of the bulk viscous coefficient which successfully describes the present-day evolution of the Universe. We observe that the model with bulk viscosity provides an elegant description of the early and late-time evolution of the Universe. We constrain the model through the combined observational data of the Strong Lensing System(SLS), measurements of Hubble parameter, Type Ia supernova data of Pantheon sample and local H0measured by SH0ES. Using best-fit values obtained from two different combinations of data, we estimate the present value of Hubble’s constant H0=71.567-0.848+1.448and H0=69.197-1.924+1.563, the deceleration parameter q0=-0.535-0.016+0.016and q0=-0.536-0.016+0.016, and the equation of state w0=-0.690-0.010+0.010and w0=-0.691-0.011+0.011, respectively. The HDE model with bulk viscosity exhibits the phase transition from decelerated epoch to accelerated epoch. A comparison of the model with the standard ΛCDM model is discussed with the statefinder and cosmographic parameters.