New special homogeneous Bianchi type I Massive string cosmological models with anisotropic dark energy

Abstract

A special law of variation for Hubble’s parameter is presented in a spatially homogeneous Bianchi type-I massive string cosmological models with space-time that yields a constant value of deceleration parameter. Using the law of variation for Hubble’s parameter, exact solutions of Einstein’s field equations are obtained for Bianchi-I space-time filled with perfect fluid in two different cases where the universe exhibits power-law and exponential expansion. It is found that the solutions are consistent with the recent observations of type Ia supernovae. A detailed study of physical and kinematical properties of the models is carried out.