The evolution of time-dependent Λ and G in multi-fluid Bianchi type-I cosmological models

Abstract

In this work, cosmological solutions based on the time-dependent cosmological ( Λ \Lambda ) and Newtonian ( G G ) running “constants” in the Bianchi type-I spacetime are investigated vis-à-vis known cosmological data. The observationally known values of Ω m , Ω r {\Omega }_{{\rm{m}}},{\Omega }_{{\rm{r}}} and Ω Λ {\Omega }_{\Lambda } have been used to solve the Einstein field equations for the model and the resulting behaviours of the physical and dynamical quantities, with particular emphasis on late-time cosmology, are discussed. Our analysis indicates that certain choices of the defining model parameters give results consistent with the observed behaviour of the universe, such as accelerated expansion and an early anisotropy that vanishes at late times.