The Bulk Viscous String Cosmology in An Anisotropic Universe With Late Time Acceleration
Abstract
A model of a cloud formed by massive strings is used as a source of Bianchi type II. We assumed that the expansion in the model is proportional to the shear . To get exact solution, we have considered the equation of state of the fluid to be in the stiff form. It is found that the bulk viscosity plays a very important rule in the history of the universe. In presence of bulk viscosity the particles dominate over strings whereas in absence of it, strings dominate over the particles which is not in consistence with the recent observations. Also we observe that the viscosity caused the expansion of the universe to be accelerating. Our models are evolving from an early decelerating phase to a late time accelerating phase. The physical and geometrical behavior of these models are discussed.
Keywords
Cite
@article{arxiv.1211.4413,
title = {The Bulk Viscous String Cosmology in An Anisotropic Universe With Late Time Acceleration},
author = {Hassan Amirhashchi},
journal= {arXiv preprint arXiv:1211.4413},
year = {2015}
}
Comments
13 pages, 7 figures. Some sentences have been changed in order to avoid the overlapping problem. arXiv admin note: substantial text overlap with arXiv:1011.6050; and with arXiv:1102.1077 by other authors