Cosmic shear in inflationary models of Bianchi types VIII and IX (Q1094295)

Two exact solutions of Einstein's field equations of vacuum are presented and investigated. We will regard the \(\Lambda\) term vacuum fluid as the limiting case of scalar field with an almost constant potential. Considering the four velocity of this fluid we find, that in both solutions there is an anisotropic expansion of the cosmic fluid, but the fluid has vanishing vorticity. We investigate whether shear could prevent the transition into an inflationary era in these models, and the effect of shear on a scalar field is also considered. It is found that shear will speed up the rollover of the scalar field in some Bianchi type-VIII models. Possible initial conditions are discussed in light of the group structures of the models.