Consequences of Holographic Dark Energy Cosmological Model in Gravity

2019 ◽  
Vol 1 (1) ◽  
pp. 49-57
Author(s):  
Salim Shekh
Keyword(s):  
Dark Energy ◽  
Bianchi Type ◽  
Holographic Dark Energy ◽  
State Parameter ◽  
Power Laws ◽  
Big Bang ◽  
Type I ◽  
Field Equations ◽  
Gravitational Field Equations ◽  
Energy Components

We have investigated the dynamics of spatially homogeneous Bianchi type-I (LRS) space-time filled with two minimally interacting fields-matter and holographic dark energy components with volumetric power laws expansion towards the gravitational field equations for the linear form of gravity. Solving the set of field equation we obtained the exact solution andobserved that the mode of expansion of the model is accelerating throughout the evolution due to destructive assessment of deceleration parameter. Also it has found that the Gauss-Bonnet invariantand the function of Gauss-Bonnet invariant both are not occur for , the equation of state parameter admits the different values for different values of n whichare relevantin the standard range provided by recent theoretical and experimental data along with the model has a Big-Bang type of singularity at singular point.

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.

A new class of holographic dark energy models in LRS Bianchi Type-I

2021 ◽  
Author(s):  
Anirudh Pradhan ◽  
Vinod Kumar Bhardwaj ◽  
Archana Dixit ◽  
Syamala Krishnannair
Keyword(s):  
Dark Energy ◽  
Bianchi Type ◽  
Holographic Dark Energy ◽  
Cosmological Solution ◽  
Type I ◽  
Field Equations ◽  
Eos Parameter ◽  
Bianchi Type I ◽  
New Class ◽  
Energy Models

In this paper, we examine the LRS Bianchi-type-I cosmological model with holographic dark energy. The exact solutions to the corresponding field equations are obtained by using the generalized hybrid expansion law (HEL). The EoS parameter [Formula: see text] for DE is found to be time-dependent and redshift-dependent and its exiting range for derived model is agreeing well with the current observations. Here, we likewise apply two mathematical diagnostics, the statefinders ([Formula: see text]) and [Formula: see text] plan to segregate HDE model from the [Formula: see text]CDM model. Here, the [Formula: see text] diagnostic trajectories are good tools to classify the dynamical DE model. We found that our model lies in both thawing region and freezing region. We also construct the potential as well as dynamics of the quintessence and tachyon scalar field. Some physical and geometric properties of this model along with the physical acceptability of cosmological solution have been discussed in detail.

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.

scholarly journals Physical Acceptability of the Renyi, Tsallis and Sharma-Mittal Holographic Dark Energy Models in the f(T,B) Gravity under Hubble’s Cutoff

Universe ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 67
Author(s):  
Salim Harun Shekh ◽  
Pedro H. R. S. Moraes ◽  
Pradyumn Kumar Sahoo
Keyword(s):  
Dark Energy ◽  
Holographic Dark Energy ◽  
Cosmological Parameters ◽  
Field Equations ◽  
Eos Parameter ◽  
Two Fluids ◽  
Gravitational Field Equations ◽  
Energy Models ◽  
Different Types ◽  
The Universe

In the present article, we investigate the physical acceptability of the spatially homogeneous and isotropic Friedmann–Lemâitre–Robertson–Walker line element filled with two fluids, with the first being pressureless matter and the second being different types of holographic dark energy. This geometric and material content is considered within the gravitational field equations of the f(T,B) (where T is the torsion scalar and the B is the boundary term) gravity in Hubble’s cut-off. The cosmological parameters, such as the Equation of State (EoS) parameter, during the cosmic evolution, are calculated. The models are stable throughout the universe expansion. The region in which the model is presented is dependent on the real parameter δ of holographic dark energies. For all δ≥4.5, the models vary from ΛCDM era to the quintessence era.

Anisotropic Dark Energy Cosmological Model with Cosmic Strings

2020 ◽  
Author(s):  
T. Vinutha ◽  
V.U.M. Rao ◽  
Molla Mengesha
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Cosmological Model ◽  
State Parameter ◽  
Accelerated Expansion ◽  
Physical Parameters ◽  
Type I ◽  
Field Equations ◽  
Eos Parameter ◽  
Phantom Divide

The present study deals with a spatially homogeneous locally rotationally symmetric (LRS) Bianchi type-I dark energy cosmological model containing one dimensional cosmic string fluid source. The Einstein's field equations are solved by using a relation between the metric potentials and hybrid expansion law of average scale factor. We discuss accelerated expansion of our model through equation of state (ωde) and deceleration parameter (q). We observe that in the evolution of our model, the equation of state parameter starts from matter dominated phase ωde > -1/3 and ultimately attains a constant value in quintessence region (-1 < ωde < -1/3). The EoS parameter of the model never crosses the phantom divide line (ωde = 1). These facts are consistent with recent observations. We also discuss some other physical parameters.

scholarly journals Kantowski–Sachs Tsallis holographic dark energy model with sign-changeable interaction

2021 ◽  
Vol 81 (11) ◽  
Author(s):  
Y. Sobhanbabu ◽  
M. Vijaya Santhi
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Deceleration Parameter ◽  
Graphical Representation ◽  
Holographic Dark Energy ◽  
State Parameter ◽  
Field Equations ◽  
Dynamical Parameters ◽  
Frame Work ◽  
The Stability

AbstractIn this work devoted to the investigation of the Tsallis holographic dark energy (IR cut-off is Hubble radius) in homogeneous and anisotropic Kantowski–Sachs Universe within the frame-work of Saez–Ballester scalar tensor theory of gravitation. We have constructed non-interacting and interacting Tsallis holographic dark energy models by solving the field equations using the relationship between the metric potentials. This relation leads to a viable deceleration parameter model which exhibits a transition of the Universe from deceleration to acceleration. In interacting case, we focus on sign-changeable interaction between Tsallis holographic dark energy and dark matter. The dynamical parameters like equation of state parameter, energy densities of Tsallis holographic dark energy and dark matter, deceleration parameter, and statefinder parameters of the models are explained through graphical representation. And also, we discussed the stability analysis of the our models.

The Mimetic Matter in LRS Bianchi Type-I Model

2021 ◽  
Author(s):  
Ertan Gudekli ◽  
E. Demir
Keyword(s):  
Bianchi Type ◽  
State Parameter ◽  
Relativity Theory ◽  
Type I ◽  
Field Equations ◽  
Bianchi Type I ◽  
Rotationally Symmetric ◽  
Bianchi Type I Universe ◽  
Expansion Of The Universe ◽  
The Universe

This paper deals with the Locally rotationally symmetric (LRS) Bianchi type-I universe model in Mimetic Gravity Theory assuming it an extended form of General Relativity Theory. It was proclaimed as a conformal transformation of the Einstein-Hilbert action from Einstein frame to Jordon frame. At the outset, we have proposed a potential function on account of clarifying the expansion of our universe by considering the general solutions of the field equations that originate from the action of the theory including the Lagrange multipliers. Lastly, after having been achieved the general equation of the state parameter ω, we discussed whether the result corresponds to some fluids illuminating the expansion of the Universe or not.

scholarly journals Invariant Bianchi type I models in f(R,T) gravity

2018 ◽  
Vol 15 (02) ◽  
pp. 1850026 ◽  
Author(s):  
Anil Kumar Yadav ◽  
Ahmad T. Ali
Keyword(s):  
Bianchi Type ◽  
Big Bang ◽  
Type I ◽  
Analysis Method ◽  
Field Equations ◽  
Bianchi Type I ◽  
Nonsingular Solution ◽  
The Big Bang ◽  
Big Bang Singularity ◽  
Special Case

In this paper, we search the existence of invariant solutions of Bianchi type I space-time in the context of [Formula: see text] gravity with special case [Formula: see text]. The exact solution of the Einstein’s field equations are derived by using Lie point symmetry analysis method that yield two models of invariant universe for symmetries [Formula: see text] and [Formula: see text]. The model with symmetries [Formula: see text] begins with big bang singularity while the model with symmetries [Formula: see text] does not favor the big bang singularity. Under this specification, we find out at set of singular and nonsingular solution of Bianchi type I model which present several other physically valid features within the framework of [Formula: see text] gravity.

Anisotropic universe and generalized ghost dark energy in Brans–Dicke theory

2016 ◽  
Vol 94 (2) ◽  
pp. 201-208 ◽  
Author(s):  
V. Fayaz ◽  
H. Hossienkhani ◽  
A. Pasqua ◽  
Z. Zarei ◽  
M. Ganji
Keyword(s):  
Dark Energy ◽  
State Parameter ◽  
Anisotropic Universe ◽  
Type I ◽  
De Sitter ◽  
Einstein Field Equations ◽  
Field Equations ◽  
Ghost Dark Energy ◽  
The Stability ◽  
Generalized Ghost Dark Energy

In this paper, we consider the generalized ghost dark energy in a Bianchi type-I metric (which is a spatially homogeneous and anisotropic) in the framework of Brans–Dicke theory. For this purpose, we use the squared sound speed [Formula: see text] the sign of which determines the stability of the model. At first, we obtain the equation of state parameter, ωΛ = pΛ/ρΛ, the deceleration parameter q and the evolution equation of the generalized ghost dark energy. We find that, in this case, ωΛ cannot cross the phantom line (ωΛ > –1) and eventually the universe approaches a de-Sitter phase of expansion (ωΛ → –1). Then, we extend our study to the case of generalized ghost dark energy in a non-isotropic and Brans–Dicke framework and find out that the transition of ωΛ to the phantom regime can be more easily accounted for than when it is restored into the Einstein field equations. In conclusion, we find evidence that the generalized ghost dark energy in BD theory can lead to a stable universe favored by observations at the present time.

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