Viscous fluid cosmology with time dependent q and $$\Uplambda$$ -term in Bianchi type-I space-time and late time acceleration.

Exact solutions of Einstein's field equations are obtained in a spatially homogeneous and anisotropic Bianchi type-I space-time in presence of a dissipative fluid with constant and time dependent cosmological term $$\Uplambda$$ . Einstein's field equations are solved by considering a time dependent deceleration parameter, which affords a late time acceleration in the universe. The cosmological constant $$\Uplambda$$ is found to be a decreasing function of time and it approaches a small positive value at present epoch, which is corroborated by consequences from recent supernovae I observations. To get the deterministic solution a barotropic equation of state together with shear viscosity, proportional to expansion scalar, is also assumed. It is observed that initial nature of singularity is not changed due to presence of viscous fluid. The basic equation of thermodynamics is deduced and thermodynamic aspects of models are discussed. Physical and geometric properties of cosmological models are also discussed. [ABSTRACT FROM AUTHOR]