scholarly journals Bianchi Types II, VIII, and IX String Cosmological Models with Bulk Viscosity in a Theory of Gravitation

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
V. U. M. Rao ◽  
K. V. S. Sireesha ◽  
M. Vijaya Santhi
Keyword(s):  
Cosmological Model ◽  
Bulk Viscosity ◽  
Bianchi Type ◽  
Cosmological Models ◽  
Geometrical Properties ◽  
Viii And Ix ◽  
Theory Of Gravitation ◽  
Spatially Homogeneous ◽  
Bianchi Types

We have obtained and presented spatially homogeneous Bianchi types II, VIII, and IX string cosmological models with bulk viscosity in a theory of gravitation proposed by Sen (1957) based on Lyra (1951) geometry. It is observed that only vacuum cosmological model exists in case of Bianchi type IX universe. Some physical and geometrical properties of the models are also 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.

scholarly journals Bianchi Type II, VIII, and IX Perfect Fluid Dark Energy Cosmological Models in Saez-Ballester and General Theory of Gravitation

2013 ◽  
Vol 2013 ◽  
pp. 1-11
Author(s):  
V. U. M. Rao ◽  
K. V. S. Sireesha ◽  
D. Neelima
Keyword(s):  
Dark Energy ◽  
Perfect Fluid ◽  
Bianchi Type ◽  
Cosmological Models ◽  
Type Ii ◽  
Geometrical Features ◽  
Viii And Ix ◽  
Theory Of Gravitation ◽  
Spatially Homogeneous ◽  
Einstein’S General Relativity

The paper deals with spatially homogeneous anisotropic Bianchi type II, VIII , and IX dark energy cosmological models filled with perfect fluid in the framework of Saez-Ballester (1986) theory, and Einstein's general relativity. Assuming that the two sources interact minimally and therefore their energy momentum tensors are conserved separately, we have considered different cases and presented anisotropic as well as isotropic cosmological models. Some important physical and geometrical features of the models, thus obtained, have been discussed.

scholarly journals Spatially Homogeneous and Anisotropic Cosmological Models in Brans-Dicke Theory

1981 ◽  
Vol 34 (3) ◽  
pp. 261 ◽  
Author(s):  
VB Johri ◽  
GK Goswami
Keyword(s):  
Bianchi Type ◽  
Cosmological Models ◽  
Type I ◽  
Bianchi Type I ◽  
Geometrical Properties ◽  
Anisotropic Cosmological Models ◽  
Spatially Homogeneous ◽  
Relativistic Models

Spatially homogeneous and anisotropic cosmological models corresponding to Bianchi type I solutions of Brans-Dicke theory are investigated. The physical and geometrical properties of the models are discussed and compared with the corresponding relativistic models.

scholarly journals Bianchi Type- I Bulk Viscosity with a DE Cosmological Model

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Daba Meshesha Gusu
Keyword(s):  
Dark Energy ◽  
Cosmological Model ◽  
Bulk Viscosity ◽  
Bianchi Type ◽  
Early Time ◽  
Observational Result ◽  
Type I ◽  
Field Equations ◽  
Geometrical Properties ◽  
The Universe

The finding article presents Bianchi type- I universe in the presence of bulk viscous and DE fluid nature of a cosmological model. The solutions of field equations were obtained by assuming hybrid expansion law. The physical significance of the obtained findings illustrates the dominance of bulk viscosity in early and dominance of dark energy fluid emergences in late. This leads to indicate the presence of bulk viscosity nature more effective in early time rather than late times, and also, it shows the dominance of dark energy in late times which grants the current observational result of the universe. Certain physical and geometrical properties of the model are also discussed.

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