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.

Magnetized anisotropic dark energy cosmological models in scale covariant theory of gravitation

2014 ◽  
Vol 23 (07) ◽  
pp. 1450065 ◽  
Author(s):  
S. D. Katore ◽  
M. M. Sancheti ◽  
S. P. Hatkar
Keyword(s):  
Dark Energy ◽  
Bianchi Type ◽  
Covariant Theory ◽  
Type Ii ◽  
Field Equations ◽  
Scale Covariant Theory ◽  
Anisotropic Dark Energy ◽  
Expansion Scalar ◽  
Viii And Ix ◽  
Theory Of Gravitation

In the present paper, we have investigated Bianchi type II, VIII and IX spacetime in the presence of magnetized anisotropic dark energy in the Scale covariant theory of gravitation. Exact solution of the field equations are obtained by assuming the expansion anisotropy (the ratio of shear scalar to expansion scalar) to be a function of average scale factor. The isotropy of the fluid, space and expansion are examined.

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.

Dynamics of Bianchi type-V anisotropic dark energy cosmological model in a scale covariant theory of gravitation

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Dandala Radhakrishna Reddy 1
Keyword(s):  
Dark Energy ◽  
Cosmological Model ◽  
Bianchi Type ◽  
Covariant Theory ◽  
Scale Covariant Theory ◽  
Anisotropic Dark Energy ◽  
Theory Of Gravitation ◽  
Type V ◽  
The Universe ◽  
Bianchi Type V

This paper is devoted to the discussion of dynamical properties of anisotropic dark energy cosmological model of the universe in a Bianchi type-V space time in the framework of scale covariant theory of gravitation formulated by Canuto et al.(phys.Rev.Lett.39:429,1977).A  dark energy cosmological model is presented by solving the field equations of this theory by using some physically viable conditions. The dynamics of the model is  studied  by computing the cosmological parameters, dark energy density, equation of state(EoS) parameter, skewness parameters, deceleration parameter and the jerk parameter. This being a scalar field model gives us the quintessence model of the universe which describes a significant dark energy candidate of our accelerating universe. All the physical quantities discussed are in agreement with the recent cosmological observations.

scholarly journals Bianchi type-III Tsallis holographic dark energy model in Saez–Ballester theory of gravitation

2020 ◽  
Vol 80 (12) ◽  
Author(s):  
M. Vijaya Santhi ◽  
Y. Sobhanbabu
Keyword(s):  
Dark Energy ◽  
Bianchi Type ◽  
Graphical Representation ◽  
Holographic Dark Energy ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Field Equations ◽  
Om Diagnostic ◽  
Hubble Radius ◽  
Theory Of Gravitation

AbstractIn this paper, we have investigated Tsallis holographic dark energy (infrared cutoff is the Hubble radius) in homogeneous and anisotropic Bianchi type-III Universe within the framework of Saez–Ballester scalar–tensor theory of gravitation. We have constructed non-interaction and interaction dark energy models by solving the Saez–Ballester field equations. To solve the field equations, we assume a relationship between the metric potentials of the model. We developed the various cosmological parameters (namely deceleration parameter q, equation of state parameter $$\omega _t$$ ω t , squared sound speed $$v_s^2$$ v s 2 , om-diagnostic parameter Om(z) and scalar field $$\phi $$ ϕ ) and well-known cosmological planes (namely $$\omega _t-\omega _t^{'}$$ ω t - ω t ′ plane, where $$'$$ ′ denotes derivative with respect to ln(a) and statefinders ($$r-s$$ r - s ) plane) and analyzed their behavior through graphical representation for our both the models. It is also, quite interesting to mention here that the obtained results are coincide with the modern observational data.

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