Axially Symmetric Bulk Viscous String Cosmological Models in GR and Brans-Dicke Theory of Gravitation

V U M Rao,D Neelima

doi:10.1155/2013/543483

Abstract

Axially symmetric string cosmological models with bulk viscosity in Brans-Dicke (1961) and general relativity (GR) have been studied. The field equations have been solved by using the anisotropy feature of the universe in the axially symmetric space-time. Some important features of the models, thus obtained, have been discussed. We noticed that the presence of scalar field does not affect the geometry of the space-time but changes the matter distribution, and as a special case, it is always possible to obtain axially symmetric string cosmological model with bulk viscosity in general relativity.

Highlights

Brans and Dicke [1] theory of gravitation is a natural extension of general relativity which introduces an additional scalar field φ besides the metric tensor gij and dimensionless coupling constant ω
We have presented axially symmetric string cosmological models with bulk viscosity in Brans-Dicke theory of gravitation and general relativity
Equation (45) shows that the density parameter Ω depends on the anisotropy parameter Am

Summary

Introduction

Brans and Dicke [1] theory of gravitation is a natural extension of general relativity which introduces an additional scalar field φ besides the metric tensor gij and dimensionless coupling constant ω. Rao and Sireesha [13, 14] have discussed axially symmetric, Bianchi type-II, -VIII, and -IX cosmological models with strange quark matter attached to string cloud in Brans-Dicke theory of gravitation, respectively. Rao et al [19,20,21] have obtained axially symmetric string, perfect fluid cosmological models, and Bianchi type-II, -VIII, and -IX magnetized cosmological models in Brans-Dicke theory of gravitation. Rao and Sireesha [24, 25] have studied a higherdimensional string, and Bianchi type-II, -VIII, and -IX string cosmological models with bulk viscosity, respectively, in Brans-Dicke theory of gravitation. Rao and Sireesha [26] have discussed axially symmetric string cosmological model with bulk viscosity in self-creation theory of gravitation. We will study axially symmetric string cosmological models with bulk viscosity in Brans-Dicke and general relativity

Axially Symmetric Metric and Field Equations

Cosmological Models

Conclusions