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.

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.

Kaluza-Klein Tilted Cosmological Model in Lyra Geometry

2017 ◽  
Vol 42 (3) ◽  
pp. 1451-1457 ◽  
Author(s):  
Subrata Kumar Sahu ◽  
Samuel Ganiamo Ganebo ◽  
Gebretsadik Gidey Weldemariam
Keyword(s):  
Cosmological Model ◽  
Lyra Geometry ◽  
Tilted Cosmological Model ◽  
Kaluza Klein

ROLE OF EXTRA DIMENSION IN ACCELERATED EXPANSION

2008 ◽  
Vol 23 (06) ◽  
pp. 909-917 ◽  
Author(s):  
K. D. PUROHIT ◽  
YOGESH BHATT
Keyword(s):  
Cosmological Model ◽  
Extra Dimension ◽  
Accelerated Expansion ◽  
Field Equations ◽  
Four Dimensions ◽  
Scale Factors ◽  
Expansion Of The Universe ◽  
The Universe ◽  
Kaluza Klein

A five-dimensional FRW-type Kaluza–Klein cosmological model is taken to study the role of extra dimension in the expansion of the universe. Relation between scale factors corresponding to conventional four dimensions and the extra dimension has been established. Field equations are solved in order to find out the effect of pressure corresponding to these scale factors. Conditions for accelerated expansion are derived.

scholarly journals ON THE ROLE OF VISCOSITY IN EARLY COSMOLOGY

2008 ◽  
Vol 23 (08) ◽  
pp. 1248-1252
Author(s):  
NAKIA CARLEVARO ◽  
GIOVANNI MONTANI
Keyword(s):  
Energy Density ◽  
Power Law ◽  
Bulk Viscosity ◽  
Viscosity Coefficient ◽  
Hydrodynamic Equations ◽  
Restricted Domain ◽  
Asymptotic Approach ◽  
Cosmological Singularity ◽  
Second Order In Time

We present a discussion of the effects induced by bulk viscosity on the very early Universe stability. The viscosity coefficient is assumed to be related to the energy density ρ via a power-law of the form ζ = ζ0ρs (where ζ0, s = const.) and the behavior of the density contrast in analyzed. In particular, we study both Einstein and hydrodynamic equations up to first and second order in time in the so-called quasi-isotropic collapsing picture near the cosmological singularity. As a result, we get a power-law solution existing only in correspondence to a restricted domain of ζ0. The particular case of pure isotropic FRW dynamics is then analyzed and we show how the asymptotic approach to the initial singularity admits an unstable collapsing picture.

scholarly journals Stability Analysis of Bulk Viscous Cosmology

2018 ◽  
Vol 168 ◽  
pp. 08006 ◽  
Author(s):  
M. Sharif ◽  
Saadia Mumtaz
Keyword(s):  
Power Law ◽  
Bulk Viscosity ◽  
Viscosity Coefficient ◽  
Study Phase ◽  
Universe Model ◽  
Power Law Model ◽  
Frw Universe ◽  
Dimensionless Variables ◽  
The Stability ◽  
Bulk Viscosity Coefficient

In this paper, we study phase space analysis of FRW universe model by taking a power-law model for bulk viscosity coefficient. An autonomous system of equations is developed by defining normalized dimensionless variables. We find corresponding critical points for di.erent values of the parameters to investigate stability of the system. It is found that the presence of power-law model of bulk viscosity appears as an e.ective ingredient to enhance the stability of the respective universe model.

STRING-DUST IN HIGHER-DIMENSIONAL CYLINDRICALLY SYMMETRIC COSMOLOGICAL MODEL

1999 ◽  
Vol 08 (05) ◽  
pp. 645-650 ◽  
Author(s):  
SUBENOY CHAKRABORTY ◽  
ANUSUA ROY
Keyword(s):  
Cosmological Model ◽  
String Cosmology ◽  
Symmetric Model ◽  
Cylindrically Symmetric ◽  
Higher Dimensional ◽  
Kaluza Klein

We have studied string cosmology in higher-dimensional cylindrically symmetric model which is in the Kaluza–Klein spacetime. Some of the solutions show a nonsingularity of the spacetime.

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.

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