scholarly journals FRW type Kaluza–Klein modified holographic Ricci dark energy models in Brans–Dicke theory of gravitation

2018 ◽  
Vol 78 (8) ◽  
Author(s):  
Y. Aditya ◽  
D. R. K. Reddy
Keyword(s):  
Dark Energy ◽  
Ricci Dark Energy ◽  
Energy Models ◽  
Theory Of Gravitation ◽  
Kaluza Klein

scholarly journals THERMODYNAMICS IN KALUZA–KLEIN UNIVERSE

2013 ◽  
Vol 28 (17) ◽  
pp. 1350072 ◽  
Author(s):  
M. SHARIF ◽  
RABIA SALEEM
Keyword(s):  
Dark Energy ◽  
Apparent Horizon ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Model Parameters ◽  
Ricci Dark Energy ◽  
Generalized Second Law ◽  
Energy Models ◽  
Fixed Radius ◽  
Kaluza Klein

This paper is devoted to check the validity of laws of thermodynamics for Kaluza–Klein universe in the state of thermal equilibrium, composed of dark matter and dark energy. The generalized holographic dark energy and generalized Ricci dark energy models are considered here. It is proved that the first and generalized second law of thermodynamics are valid on the apparent horizon for both of these models. Further, we take a horizon of radius L with modified holographic or Ricci dark energy. We conclude that these models do not obey the first and generalized second law of thermodynamics on the horizon of fixed radius L for a specific range of model parameters.

Kaluza-Klein FRW dark energy models in Saez-Ballester theory of gravitation

New Astronomy ◽  
2020 ◽  
pp. 101564
Author(s):  
R.L. Naidu ◽  
Y. Aditya ◽  
K. Deniel Raju ◽  
T. Vinutha ◽  
D.R.K. Reddy
Keyword(s):  
Dark Energy ◽  
Energy Models ◽  
Theory Of Gravitation ◽  
Kaluza Klein

scholarly journals Sandage–Loeb test for the new agegraphic and Ricci dark energy models

2010 ◽  
Vol 691 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Jingfei Zhang ◽  
Li Zhang ◽  
Xin Zhang
Keyword(s):  
Dark Energy ◽  
Ricci Dark Energy ◽  
Energy Models

Anisotropic Bianchi type-II modified holographic Ricci dark energy model in scale-covariant theory of gravitation

2021 ◽  
Author(s):  
Shri Ram ◽  
S. Chandel ◽  
M.K. Verma
Keyword(s):  
Dark Energy ◽  
Bianchi Type ◽  
Covariant Theory ◽  
Type Ii ◽  
Field Equations ◽  
Ricci Dark Energy ◽  
Scale Covariant Theory ◽  
Cosmological Observations ◽  
Negative Constant ◽  
Theory Of Gravitation

In this paper, we obtain an anisotropic Bianchi type-II space-time with dark matter and the modified holographic Ricci dark energy in the scale-covariant theory of gravitation. Exact solutions of the field equations are obtained by assuming (I) a negative constant value of the deceleration parameter (II) the component σ<sup>1</sup><sub>1</sub> of the shear tensor σ<sup>j</sup><sub>i</sub> is proportional to the mean Hubble parameter and (III) the gauge function Φ is proportional to a power function of the average scale factor. We have also discussed some important physical aspects of the model which is in agreement with the modern cosmological observations.

Anisotropic dark energy models in Brans Dicke theory of gravitation with different expansion laws: A comparative study

2020 ◽  
Vol 34 (06) ◽  
pp. 2050030
Author(s):  
Mukesh Kumar ◽  
Rekha Jaiswal ◽  
Rashid Zia
Keyword(s):  
Dark Energy ◽  
Comparative Study ◽  
Field Equations ◽  
Anisotropic Dark Energy ◽  
Energy Models ◽  
Scale Factors ◽  
Tensor Theory ◽  
Rotationally Symmetric ◽  
Theory Of Gravitation ◽  
General Scale

In this paper, we have derived the general solutions of the field equations of the Scalar–Tensor theory of gravitation, proposed by Brans and Dicke (1961) within the framework of a locally rotationally symmetric (LRS) metric. We have discussed the anisotropic dark energy models by assuming the time-dependent general scale factor [Formula: see text]. Further, we have discussed the physical and geometric behaviors of the model using different forms of the scale factors. We have also performed a comparative study of the results obtained in various cases. We have observed that the solutions obtained using Hybrid Expansion Law (HEL) are more consistent with recent observations as compared to the rest. Stability of the solutions is also compared using metric perturbations.

Sign in / Sign up

Export Citation Format

Share Document