Nonlinear Spinor Fields in Bianchi Type-V Spacetime

A self-consistent system of nonlinear spinor and Bianchi type-V anisotropic gravitational fields are investigated. It is found that the presence of nontrivial non-diagonal components of the energy-momentum tensor of the spinor field imposes some severe restrictions on the system. As a result two different solutions are found. In one case the metric functions are similar to each other, i.e., a(1) similar to a(2) similar to a(3) and the spinor mass and spinor field nonlinearity do not disappear from the system. In this case the spacetime expands with acceleration in case of a positive self-coupling constant lambda. A negative A gives rise to a cyclic or periodical mode of expansion. In the second case the spinor mass and the spinor field nonlinearity vanish and the Universe expands linearly with time.