Higher-dimensional cosmological model with variable gravitational constant and bulk viscosity in Lyra geometry

Pramana ◽  
2004 ◽  
Vol 63 (5) ◽  
pp. 937-945 ◽  
Author(s):  
G. P. Singh ◽  
R. V. Deshpande ◽  
T. Singh
Keyword(s):  
Cosmological Model ◽  
Bulk Viscosity ◽  
Gravitational Constant ◽  
Lyra Geometry ◽  
Higher Dimensional

HIGHER DIMENSIONAL COSMOLOGICAL MODEL IN LYRA GEOMETRY: REVISITED

2003 ◽  
Vol 12 (05) ◽  
pp. 853-860 ◽  
Author(s):  
G. P. SINGH ◽  
S. KOTAMBKAR ◽  
ANIRUDH PRADHAN
Keyword(s):  
Cosmological Model ◽  
Power Law ◽  
Bulk Viscosity ◽  
Research Work ◽  
Lyra Geometry ◽  
Universe Model ◽  
Higher Dimensional ◽  
Empty Universe ◽  
Kaluza Klein

In this paper we have revisited the research work of Rahman and Bera22on Kaluza–Klein cosmological model within the framework of Lyra Geometry. It has been shown that the empty universe model yields a power law relation without any assumption. The role of bulk viscosity on five-dimensional cosmological model is discussed. The physical behaviour of the models is examined in all cases.

STRING DUST COSMOLOGICAL MODEL IN HIGHER-DIMENSIONAL SPACE–TIME

2005 ◽  
Vol 14 (09) ◽  
pp. 1621-1634 ◽  
Author(s):  
G. S. KHADEKAR ◽  
VRISHALI PATKI ◽  
R. RADHA
Keyword(s):  
Cosmological Model ◽  
Bulk Viscosity ◽  
Dimensional Space ◽  
Space Time ◽  
Isotropic Universe ◽  
Bulk Viscous Fluid ◽  
Higher Dimensional Space Time ◽  
Higher Dimensional ◽  
Dimensional Space Time ◽  
Shear Scalar

We have investigated the bulk viscous fluid string dust cosmological model in the higher dimensional space–time. To obtain a determinate solution, it is assumed that the coefficient of bulk viscosity is a power function of the energy density τ = τcρm(t) and the scalar of expansion is proportional to shear scalar, which leads to a relation between metric potentials A = KRn where A and R are functions of time. It is also observed that models appear to be singular at [Formula: see text] and [Formula: see text] in the presence and absence of bulk viscosity and for n = 1, the model represent an isotropic universe. The physical and geometrical aspects of the model are also discussed.

Locally rotationally symmetric (LRS) Bianchi type II string dust viscous fluid cosmological models in Lyra geometry

2014 ◽  
Vol 92 (12) ◽  
pp. 1714-1719 ◽  
Author(s):  
Raj Bali ◽  
Mahesh Kumar Yadav ◽  
Lokesh Kumar Gupta
Keyword(s):  
Cosmological Model ◽  
Viscous Fluid ◽  
Bulk Viscosity ◽  
Bianchi Type ◽  
Displacement Vector ◽  
Lyra Geometry ◽  
Type Ii ◽  
Locally Rotationally Symmetric ◽  
Rotationally Symmetric ◽  
The Universe

In the present study, a locally rotationally symmetric Bianchi type II string dust cosmological model with varying bulk viscosity in the framework of Lyra geometry is investigated. To get the deterministic solution, we have assumed that shear (σ) is proportional to the expansion (θ) and ζθ = constant, where ζ is the coefficient of bulk viscosity. The ansatz ζθ = constant, was found to coincide with the occurrence of Little Rip (LR) cosmology using Friedmann–Robertson–Walker metric (Breviket al. Phys. Rev. D, 84, 103508-1-6 (2011)). The model describes the pre-inflationary stage of the universe. The presence of viscosity leads to inflationary-like solutions. Anisotropy is maintained because of the presence of strings. The presence of bulk viscosity prevents the matter density from vanishing. In a special case, the model represents the isotropy of the universe. The universe passes through a decelerating stage to an accelerating phase, which is in agreement with Ries et al.’s (Astrophys. J. 607, 665 (2004). doi:10.1086/383612 ) type Ia supernovae astronomical observations. The displacement vector (β) of Lyra geometry is a decreasing function of time analogous to the cosmological constant (Λ) of general relativity. We have attempted to explore the possibility of constructing a string dust viscous fluid cosmological model in Bianchi type II space–time with displacement vector (β) in Lyra geometry using the geometric condition that shear is proportional to expansion.

HIGHER DIMENSIONAL COSMOLOGICAL MODEL IN LYRA GEOMETRY

2001 ◽  
Vol 10 (05) ◽  
pp. 729-733 ◽  
Author(s):  
FAROOK RAHAMAN ◽  
JAYANTA KUMAR BERA
Keyword(s):  
Cosmological Model ◽  
Lyra Geometry ◽  
Physical Behavior ◽  
Perfect Fluids ◽  
Higher Dimensional ◽  
Kaluza Klein

In this paper Kaluza–Klein cosmological model within the framework of Lyra geometry has been discussed. The physical behavior of the model is examined in vacuum and in the presence of perfect fluids.

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