scholarly journals Five dimensional cosmological models in Lyra geometry with time dependent displacement field

2008 ◽  
Vol 317 (3-4) ◽  
pp. 283-283 ◽  
Author(s):  
G. Mohanty ◽  
K. L. Mahanta ◽  
B. K. Bishi
Keyword(s):  
Displacement Field ◽  
Lyra Geometry ◽  
Cosmological Models ◽  
Time Dependent

Cosmological Models in Lyra Geometry with Linearly Varying Deceleration Parameter

2018 ◽  
Author(s):  
Kalyani Desikan
Keyword(s):  
Exact Solutions ◽  
Displacement Field ◽  
Deceleration Parameter ◽  
Lyra Geometry ◽  
Cosmological Models ◽  
Time Dependent ◽  
Linearly Varying Deceleration Parameter ◽  
Frw Model ◽  
Time Periods ◽  
The Universe

Cosmological models with linearly varying deceleration parameter in the cosmological theory based on Lyra’s geometry have been discussed. Exact solutions have been obtained for a spatially flat FRW model by considering a time dependent displacement field. We have also obtained the time periods during which the universe undergoes decelerated and accelerated expansions for a matter-dominated universe.

scholarly journals Kaluza-Klein FRW cosmological models in Lyra manifold

2009 ◽  
Vol 36 (2) ◽  
pp. 157-166 ◽  
Author(s):  
G. Mohanty ◽  
G.C. Samanta ◽  
K.L. Mahanta
Keyword(s):  
Perfect Fluid ◽  
Displacement Field ◽  
Arbitrary Constant ◽  
Matter Field ◽  
Cosmological Models ◽  
Time Dependent ◽  
Infinite Time ◽  
Lyra Manifold ◽  
Kaluza Klein

We have constructed five dimensional FRW cosmological models for k=-1,1,0 in Lyra manifold with time dependent displacement field. The matter field is considered in the form of a perfect fluid with isotropic matter pressure. It is found that the model for k=-1 is inflationary. For k=1, the model is inflationary for set of values of arbitrary constant n and decelerates in the standard way for another set of values of n. Moreover the concept of Lyra manifold does not exist at infinite time.

scholarly journals FLRW Cosmological Models in Lyra's Manifold with Time Dependent Displacement Field

1988 ◽  
Vol 41 (6) ◽  
pp. 833 ◽  
Author(s):  
A Beesham
Keyword(s):  
Asymptotic Behaviour ◽  
Displacement Field ◽  
Riemannian Geometry ◽  
Cosmological Models ◽  
Time Dependent ◽  
Lyra’S Manifold ◽  
Standard Models ◽  
Horizon Problems

Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmological models are derived in Lyra's manifold assuming a time dependent displacement field. The models obtained solve the singularity, entropy and horizon problems which exist in the standard models of cosmology based on Riemannian geometry. The asymptotic behaviour of the models is also examined.

scholarly journals Geometries with mismatched branes

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Andreas Karch ◽  
Lisa Randall
Keyword(s):  
Boundary Conditions ◽  
Effective Action ◽  
Cosmological Models ◽  
Time Dependent ◽  
De Sitter ◽  
Stabilization Mechanism ◽  
New Class ◽  
Vacuum Solutions ◽  
Single Coordinate

Abstract We study Randall-Sundrum two brane setups with mismatched brane tensions. For the vacuum solutions, boundary conditions demand that the induced metric on each of the branes is either de Sitter, Anti-de Sitter, or Minkowski. For incompatible boundary conditions, the bulk metric is necessarily time-dependent. This introduces a new class of time-dependent solutions with the potential to address cosmological issues and provide alternatives to conventional inflationary (or contracting) scenarios. We take a first step in this paper toward such solutions. One important finding is that the resulting solutions can be very succinctly described in terms of an effective action involving only the induced metric on either one of the branes and the radion field. But the full geometry cannot necessarily be simply described with a single coordinate patch. We concentrate here on the time- dependent solutions but argue that supplemented with a brane stabilization mechanism one can potentially construct interesting cosmological models this way. This is true both with and without a brane stabilization mechanism.

Bianchi Type I String Dust Magnetized Cosmological Models in Lyra Geometry

2010 ◽  
Vol 54 (1) ◽  
pp. 197-202 ◽  
Author(s):  
Raj Bali ◽  
Naresh K Chandnani ◽  
Lokesh Kumar Gupta
Keyword(s):  
Bianchi Type ◽  
Lyra Geometry ◽  
Cosmological Models ◽  
Type I ◽  
Bianchi Type I

Hypersurface-homogeneous cosmological models with dynamical equation of state parameter in Lyra geometry

2015 ◽  
Vol 93 (10) ◽  
pp. 1100-1105 ◽  
Author(s):  
Shri Ram ◽  
S. Chandel ◽  
M.K. Verma
Keyword(s):  
Dynamical Equation ◽  
State Parameter ◽  
Lyra Geometry ◽  
Cosmological Models ◽  
Anisotropic Fluid ◽  
Late Time ◽  
Field Equations ◽  
Homogeneous Cosmological Models ◽  
Negative Constant ◽  
Equation Of State Parameter

The hypersurface homogeneous cosmological models are investigated in the presence of an anisotropic fluid in the framework of Lyra geometry. Exact solutions of field equations are obtained by applying a special law of variation for mean Hubble parameter that gives a negative constant value of the deceleration parameter. These solutions correspond to anisotropic accelerated expanding cosmological models that isotropize for late time even in the presence of anisotropic fluid. The anisotropy of the fluid also isotropizes at late time. Some physical and kinematical properties of the model are also discussed.

scholarly journals LITTLE RIP COSMOLOGICAL MODELS WITH TIME-DEPENDENT EQUATION OF STATE

2012 ◽  
Vol 27 (36) ◽  
pp. 1250210 ◽  
Author(s):  
I. BREVIK ◽  
V. V. OBUKHOV ◽  
K. E. OSETRIN ◽  
A. V. TIMOSHKIN
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Cosmological Models ◽  
Time Dependent ◽  
De Sitter Spacetime ◽  
De Sitter ◽  
Energy Models ◽  
Sitter Spacetime ◽  
The Universe ◽  
Far Future

Specific dark energy models, leading to the Little Rip (LR) cosmology in the far future, are investigated. Conditions for the occurrence of LR in terms of the parameters present in the proposed equation of state for the dark energy cosmic fluid are studied. Estimates about the time needed before the occurrence of the small singularity in the standard LR model in which the universe approaches the de Sitter spacetime asymptotically, are given.

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