Dirac Spinor in Bianchi-I Universe with Time Dependent Gravitational and Cosmological Constants

Abstract

Self-consistent system of nonlinear spinor field and Bianchi I (BI) gravitational one with time dependent gravitational constant ($G$) and cosmological constant ($Λ$) has been studied. The initial and the asymptotic behaviors of the field functions and the metric one have been thoroughly investigated. Given $Λ= Λ_0/τ^2$, with $τ= \sqrt{-g}$, $G$ has been estimated as a function of $τ$. The role of perfect fluid at the initial state of expansion and asymptotical isotropization process of the initailly anisotropic universe has been elucidated.