Bianchi Type I Bulk Viscous Fluid Cosmological Models with Varying Cosmological Term Λ

Abstract

Bulk viscous Bianchi type I Cosmological models with varying cosmological term Λ in general relativity are investigated. To get a determinate Einstein exact solution, we have assumed the condition that cosmological term Λ = Λ₀H, deceleration parameter q = n (constant) and ζ= ζ₀ + ζ₁H, where Λ₀, ζ₀, and ζ₁ are constant, ρ is the energy density and  z is the coefficient of bulk viscosity. The deceleration parameter q is constant throughout the model of the universe. The cosmological term Λ is a decreasing function of time. The ratio σ/θ is initially highly anisotropic and late time isotropic. Further the physical and geometrical significance of the model of universe are discussed.