Bianchi Type V Universe with Bulk Viscous Matter and Time Varying Gravitational and Cosmological Constants

摘要

Spatially homogeneous and anisotropic Bianchi type V space-time with bulkviscous fluid source and time varying gravitational constant $G$ andcosmological term $\Lambda$ are considered. Coefficient of bulk viscosity$\zeta$ is assumed as a simple linear function of Hubble parameter $H$ (i.e.$\zeta=\zeta_0+\zeta_1 H$, where $\zeta_0$ and $\zeta_1$ are constants). TheEinstein field equations are solved explicitly by using a law of variation forthe Hubble parameter, which yields a constant value of deceleration parameter.Physical and kinematical parameters of the models are discussed. The models arefound to be compatible with the results of astronomical observations.