SOME VISCOUS-FLUID COSMOLOGICAL MODELS IN GENERAL-RELATIVITY

The motivation of this paper is to investigate two viscous fluid cosmo logical models in General Relativity in which the expansion is only in two directions i.e. one of the Hubble parameters (H-1 = A(4)/A) is ze ro. In the first model, coefficient of shear viscosity is assumed to b e constant while In the second model, the coefficient of shear viscosi ty is proportional to the rate of expansion in the model. Here no addi tional condition is assumed except for coefficient of shear viscosity. These models are new and different from those models obtained by Ball and Jain (1987, 1988) in which free gravitational held was assumed to be Petrov Type D and non-degenerate for Marder (1958) metric and coef ficient of shear viscosity is proportional to the rate of expansion in the model. The various physical and geometrical aspects of the models are also discussed.