Viscous cosmology in the Kasner metric

A Bianchi type-I metric of the Kasner form is used as input in Einstein's equations to explore which consequences thereby occur for the equation of state for the cosmic fluid. Both shear viscosity and bulk viscosity coefficients are assumed to be present. The solutions of Einstein's equations can naturally be categorized into two classes. Either the space becomes anisotropic, and the equation of state is determined once the Kasner parameters p(i) are given. Or the space becomes isotropic, and the equation of state emerges in the conventional form p/rho = gamma-1 with a definite value of gamma. We also calculate the rate of entropy production (sigma) overdot per particle, and find that (sigma) overdot becomes as large as of order 10(4) s(-1) if we go back to the very early universe, t similar to 10(-4) s. We also discuss the possibility of testing the anisotropy of the universe by means of redshift experiments.