LRS Bianchi Type II Bulk Viscous Fluid Universe with Decaying Vacuum Energy Density I⟩

The present study deals with spatially homogeneous and locally rotationally symmetric (LRS) Bianchi type II cosmological models with bulk viscous fluid distribution of matter and decaying vacuum energy density I >. To get the deterministic models of the universe, we assume that the expansion (theta) in the model is proportional to the shear (sigma). This leads to condition R=mS (n) , where R and S are metric potentials, m and n are constants. We have obtained two types of models of the universe for two different values of n. The vacuum energy density I > for both models is found to be a decreasing function of time and it approaches a small positive value at late time which is supported by recent results from the observations of (SN Ia). Some physical and geometric behaviour of these models are also discussed.