Five-Dimensional Anisotropic Bianchi Type-I Models in String Cosmology

Abstract

The present study deals with a spatially homogeneous and anisotropic five dimensional Bianchi – I cosmological models representing massive string. The energy momentum tensor, as formulated by Letelier (1983) has been used to construct massive string cosmological models for which we assume the expansion scalar in the models is proportional to one of the components of shear tensor. The five dimensional Einstein’s field equations have been solved by applying the variation law for generalized Hubble’s parameter in five dimensional Bianchi-I space-time. The comparative study of accelerating and decelerating models has been made in the presence of string scenario. It is found that massive strings dominate in the decelerating universe whereas strings dominate in the accelerating universe. Also we observed that the string eventually disappear from the universe for sufficiently large times.