scholarly journals String cosmological models with bulk viscosity in Nordtvedt's general scalar-tensor theory of gravitation

2013 ◽  
Vol 7 (1) ◽  
pp. 50 ◽  
Author(s):  
Uma Maheswara Velagapudi ◽  
Neelima Davuluri
Keyword(s):  
Bulk Viscosity ◽  
Cosmological Models ◽  
Scalar Tensor Theory ◽  
Tensor Theory ◽  
General Scalar ◽  
Theory Of Gravitation

scholarly journals Kantowski-Sachs String Cosmological Model with Bulk Viscosity in General Scalar Tensor Theory of Gravitation

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
V. U. M. Rao ◽  
D. Neelima
Keyword(s):  
Bulk Viscosity ◽  
Cosmological Models ◽  
Scalar Tensor Theory ◽  
New Class ◽  
Tensor Theory ◽  
Present Universe ◽  
General Scalar ◽  
Theory Of Gravitation ◽  
Spatially Homogeneous ◽  
Special Case

A new class of spatially homogeneous Kantowski-Sachs string cosmological models with bulk viscosity in Nordtvedt (1970) general scalar-tensor theory of gravitation with the help of a special case proposed by Schwinger (1970) is obtained. In this paper we have presented anisotropic as well as isotropic cosmological models. Some important features of the models, thus obtained, have been discussed. These exact models are new and more general and represent not only the early stages of evolution but also the present universe.

scholarly journals LRS Bianchi Type-I Dark Energy Cosmological Models in General Scalar Tensor Theory of Gravitation

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
V. U. M. Rao ◽  
D. Neelima
Keyword(s):  
Dark Energy ◽  
Bianchi Type ◽  
Cosmological Models ◽  
Type I ◽  
Scalar Tensor Theory ◽  
Eos Parameter ◽  
Bianchi Type I ◽  
Tensor Theory ◽  
General Scalar ◽  
Theory Of Gravitation

Locally rotationally symmetric (LRS) Bianchi type-I dark energy cosmological model with variable equation of state (EoS) parameter in (Nordtvedt 1970) general scalar tensor theory of gravitation with the help of a special case proposed by (Schwinger 1970) is obtained. It is observed that these anisotropic and isotropic dark energy cosmological models always represent an accelerated universe and are consistent with the recent observations of type-Ia supernovae. Some important features of the models, thus obtained, have been discussed.

scholarly journals Bianchi Types II, VIII, and IX String Cosmological Models in Brans-Dicke Theory of Gravitation

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
V. U. M. Rao ◽  
M. Vijaya Santhi
Keyword(s):  
Energy Density ◽  
Cosmological Model ◽  
Bianchi Type ◽  
Cosmological Models ◽  
Scalar Tensor Theory ◽  
Tensor Theory ◽  
Geometrical Features ◽  
Viii And Ix ◽  
Theory Of Gravitation ◽  
Bianchi Types

Bianchi types II, VIII, and IX string cosmological models are obtained and presented in a scalar-tensor theory of gravitation proposed by Brans and Dicke (1961) for λ+ρ=0. We also established the existence of only Bianchi type IX vacuum cosmological model for λ=ρ, where λ and ρ are tension density and energy density of strings, respectively. Some physical and geometrical features of the models are also discussed.

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