scholarly journals Kantowski–Sachs modified holographic Ricci dark energy model in Saez–Ballester theory of gravitation

2018 ◽  
Vol 96 (5) ◽  
pp. 555-559 ◽  
Author(s):  
M.P.V.V. Bhaskar Rao ◽  
D.R.K. Reddy ◽  
K. Sobhan Babu
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Field Equations ◽  
Ricci Dark Energy ◽  
Dark Energy Density ◽  
Physical Behavior ◽  
Tensor Theory ◽  
Theory Of Gravitation ◽  
Kinematical Parameters ◽  
Energy Components

We have considered Kantowski–Sachs space–time in the presence of matter and anisotropic modified holographic Ricci dark energy components in the scalar–tensor theory of gravitation formulated by Saez and Ballester (Phys. Lett. A, 113, 467, 1986) and derived the field equations of the theory. We have used (i) hybrid expansion law proposed by Akarsu et al. (JCAP, 022, 2014), (ii) a relation between metric potentials, and (iii) modified holographic Ricci dark energy density given by Chen and Jing (Phys. Lett. B, 679, 144, 2009) to obtain an exact solution of the field equations that describes a Kantowski–Sachs holographic modified Ricci dark energy universe in this theory. Physical and kinematical parameters are also computed and their physical behavior is discussed.

scholarly journals A modified holographic Ricci dark energy model in a self-creation cosmology

2016 ◽  
Vol 94 (12) ◽  
pp. 1314-1318 ◽  
Author(s):  
M.P.V.V. Bhaskara Rao ◽  
D.R.K. Reddy ◽  
K. Sobhan Babu
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Bianchi Type ◽  
Energy Model ◽  
Smooth Transition ◽  
Type Ii ◽  
Field Equations ◽  
Ricci Dark Energy ◽  
Theory Of Gravitation ◽  
The Universe

This paper deals with a locally rotationally symmetric Bianchi type II space–time with dark matter and anisotropic modified holographic Ricci dark energy as source in second self-creation theory of gravitation proposed by Barber (Gen. Relativ. Gravit. 14, 117 (1982)). To solve the field equations of this theory we have used (i) hybrid expansion law, (ii) a relation between metric potentials and a modified holographic Ricci dark energy given by Chen and Jing (Phys. Lett. B, 679, 144 (2009)). The solution obtained represents a Bianchi type II modified holographic dark energy model in self-creation cosmology. We observe that there is a smooth transition of the universe from decelerated phase to accelerated phase. This fact is in good agreement with the observations of modern cosmology. We have also discussed some important physical aspects of the model.

Holographic dark energy model in Bianchi type VI0 Universe in a scalar–tensor theory of gravitation with hybrid expansion law

2016 ◽  
Vol 94 (12) ◽  
pp. 1338-1343 ◽  
Author(s):  
D.R.K. Reddy ◽  
S. Anitha ◽  
S. Umadevi
Keyword(s):  
Dark Energy ◽  
Bianchi Type ◽  
Holographic Dark Energy ◽  
Space Time ◽  
Scalar Tensor Theory ◽  
Field Equations ◽  
Tensor Theory ◽  
Theory Of Gravitation ◽  
The Universe ◽  
Energy Components

In this paper, we have obtained field equations of Sáez–Ballester (Phys. Lett. A, 113, 467 (1986)) scalar–tensor theory in the presence of two minimally interacting fields; matter and holographic dark energy components in the space–time described by a spatially homogeneous and anisotropic Bianchi type VI0 space–time. We have used the hybrid expansion law, proposed by Akarsu et al. (JCAP, 01, 022 (2014)), to obtain a determinate solution of the field equations. This solution represents a minimally interacting Bianchi type VI0 Sáez–Ballester universe. Physical and kinematical properties of the universe are also studied.

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.

scholarly journals Bianchi type-VI0 modified holographic Ricci dark energy model in a scalar–tensor theory

2017 ◽  
Vol 95 (2) ◽  
pp. 179-183 ◽  
Author(s):  
M. Vijaya Santhi ◽  
V.U.M. Rao ◽  
Y. Aditya
Keyword(s):  
Dark Energy ◽  
Bianchi Type ◽  
Scalar Tensor Theory ◽  
Field Equations ◽  
Ricci Dark Energy ◽  
Tensor Theory ◽  
Expansion Scalar ◽  
Shear Scalar ◽  
Average Scale Factor ◽  
Good Agreement

In this paper, we consider Bianchi type-VI0 space–time filled with anisotropic modified holographic Ricci dark energy in a scalar–tensor theory proposed by Brans–Dicke (Phys. Rev. 124, 925 (1961)). The field equations in this scalar–tensor theory, have been solved for the following physically relevant assumptions: (i) the scalar field ([Formula: see text]) is proportional to average scale factor (a(t)), (ii) expansion scalar (θ) in the model is proportional to shear scalar (σ). It has been observed that the presented universe is in an accelerating phase at the present epoch, which is in good agreement with the recent astronomical observations. We have also discussed some other properties of the obtained model.

Sign in / Sign up

Export Citation Format

Share Document