scholarly journals Cosmological Analysis of Modified Holographic Ricci Dark Energy in Chern-Simons Modified Gravity

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Sarfraz Ali ◽  
M. Jamil Amir
Keyword(s):  
Dark Energy ◽  
Modified Gravity ◽  
Dark Energy Model ◽  
State Parameter ◽  
Scalar Fields ◽  
Energy Model ◽  
Accelerated Expansion ◽  
Ricci Dark Energy ◽  
Dominant Component ◽  
Chern Simons

In this paper, we study the cosmological analysis of the modified holographic Ricci dark energy model and reconstruct different scalar field models in the context of Chern-Simons modified gravity. We investigate the deceleration parameter, which shows that the universe is in the accelerating expansion phase. The equation of state parameter in this case also favors the fact that dark energy is the dominant component of universe, which is responsible for the accelerated expansion. A number of scalar fields, such as quintessence, tachyon, K-essence, and dilaton models, are reconstructed using modified holographic Ricci dark energy model in the context of dynamical CS modified gravity. The quintessence and K-essence models represent exponentially increasing behaviors, while tachyon model shows decreasing behavior. Unfortunately, the dilaton model has no numerical solution for modified holographic Ricci dark energy model in the framework of dynamical Chern-Simons modified gravity.

scholarly journals Cosmological Implications of the Generalized Entropy Based Holographic Dark Energy Models in Dynamical Chern-Simons Modified Gravity

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
M. Younas ◽  
Abdul Jawad ◽  
Saba Qummer ◽  
H. Moradpour ◽  
Shamaila Rani
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Modified Gravity ◽  
Dark Energy Model ◽  
State Parameter ◽  
Energy Model ◽  
Evolutionary Equation ◽  
Energy Models ◽  
Equation Of State Parameter ◽  
Chern Simons

Recently, Tsallis, Rényi, and Sharma-Mittal entropies have widely been used to study the gravitational and cosmological setups. We consider a flat FRW universe with linear interaction between dark energy and dark matter. We discuss the dark energy models using Tsallis, Rényi, and Sharma-Mittal entropies in the framework of Chern-Simons modified gravity. We explore various cosmological parameters (equation of state parameter, squared sound of speed ) and cosmological plane (ωd-ωd′, where ωd′ is the evolutionary equation of state parameter). It is observed that the equation of state parameter gives quintessence-like nature of the universe in most of the cases. Also, the squared speed of sound shows stability of Tsallis and Rényi dark energy model but unstable behavior for Sharma-Mittal dark energy model. The ωd-ωd′ plane represents the thawing region for all dark energy models.

Constraints on the Ricci dark energy cosmologies in Bianchi type I model

2021 ◽  
pp. 2150095
Author(s):  
H. Hossienkhani ◽  
N. Azimi ◽  
H. Yousefi
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Bianchi Type ◽  
Energy Model ◽  
Accelerated Expansion ◽  
Likelihood Method ◽  
Type I ◽  
Ricci Dark Energy ◽  
Bianchi Type I ◽  
The Impact

The impact of anisotropy on the Ricci dark energy cosmologies is investigated where it is assumed that the geometry of the universe is described by Bianchi type I (BI) metric. The main goal is to determine the astrophysical constraints on the model by using the current available data as type Ia supernovae (SNIa), the Baryon Acoustic Oscillation (BAO), and the Hubble parameter [Formula: see text] data. In this regard, a maximum likelihood method is applied to constrain the cosmological parameters. Combining the data, it is found out that the allowed range for the density parameter of the model stands in [Formula: see text]. With the help of the Supernova Legacy Survey (SNLS) sample, we estimate the possible dipole anisotropy of the Ricci dark energy model. Then, by using a standard [Formula: see text] minimization method, it is realized that the transition epoch from early decelerated to current accelerated expansion occurs faster in Ricci dark energy model than [Formula: see text]CDM model. The results indicate that the BI model for the Ricci dark energy is consistent with the observational data.

scholarly journals Ghost Dark Energy Model with Non-linear Interaction

2018 ◽  
Vol 20 (1) ◽  
pp. 10
Author(s):  
SISTEMAS REVISTAS ◽  
Alexander Oliveros Garcia
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
State Parameter ◽  
Energy Model ◽  
Accelerated Expansion ◽  
Coupling Constant ◽  
Dark Energy Density ◽  
Small Perturbations ◽  
Linear Interaction ◽  
Non Linear

In this paper we study a dark energy model taking into account a non-linear interaction between the dark energy and dark matter components. The non-linear interaction term, used in this work, is proportional to the square of dark energy density. Considering a FRW type flat universe, we obtain an analytical expression for the Hubble parameter H and from this quantity, the deceleration parameter q and the equation of state parameter w Λ are analyzed. We found that, in this scenario, the accelerated expansion regime of the universe in late times is possible. However, using suitable values for the coupling constant, the square of the speed of sound remains negative, therefore, the model is unstable under small perturbations.

Generalized interaction term inspired dark energy model in fractal universe

2020 ◽  
Vol 35 (15) ◽  
pp. 2050126
Author(s):  
Abdul Jawad ◽  
Saba Qummer ◽  
Shamaila Rani ◽  
M. Younas
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Energy Model ◽  
Linear Term ◽  
Accelerated Expansion ◽  
Linear Interaction ◽  
Interaction Term ◽  
The Universe

By assuming generalized nonlinear and linear interaction term between dark matter and dark energy, we investigate the cosmic accelerated expansion of the universe. For this reason, we suppose a flat fractal universe platform as well as Tsallis holographic dark energy model. The Hubble horizon is being adopted as an infrared cutoff and extracted different cosmological parameters as well as plane. It is observed that equation-of-state parameter exhibits the quintom-like nature while ([Formula: see text]–[Formula: see text]) lies in thawing and freezing regions for different parametric values for both the cases. Furthermore, the squared sound speed shows stable behavior for nonlinear interaction term but shows the partially stable behavior for linear term. For both cases, the deceleration parameter leads to the accelerated phase of the universe and the consequences are comparable with observational data. The results for [Formula: see text]–[Formula: see text] plane, leads to the quintessence and phantom region of the universe for nonlinear case while this plane represents the Chaplygin gas behavior for linear term. The [Formula: see text] diagnostic also shows the satisfying results.

scholarly journals Reconstruction of the New Agegraphic Polytropic Gas Dark Energy Model in the Flat Friedmann Robertson Walker (FRW) Universe

2021 ◽  
Vol 13 (3) ◽  
pp. 779-784
Author(s):  
P. Das ◽  
K. P. Singh
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Scalar Fields ◽  
Energy Model ◽  
Accelerated Expansion ◽  
Frw Universe ◽  
Agegraphic Dark Energy ◽  
New Agegraphic Dark Energy ◽  
Polytropic Gas ◽  
Friedmann Robertson Walker

In this paper, we study the Polytropic Gas Dark Energy model and New Agegraphic Dark Energy model in the flat Friedmann Robertson Walker (FRW) Universe and establish a correspondence between them for the scalar fields. This correspondence allows reconstructing the potential of the Polytropic Gas scalar fields and dynamics of the scalar fields according to the evolutions of the New Agegraphic Dark Energy, which describes the accelerated expansion of the Universe.

scholarly journals Amended FRW Metric and Rényi Dark Energy Model

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Sarfraz Ali ◽  
Sabir Iqbal ◽  
Khuram Ali Khan ◽  
Hamid Reza Moradi
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Modified Gravity ◽  
Dark Energy Model ◽  
Holographic Dark Energy ◽  
Energy Model ◽  
Field Equations ◽  
First Case ◽  
Chern Simons ◽  
The Universe

This article is devoted to exploring the Rényi holographic dark energy model in the theory of Chern-Simons modified gravity. We studied the deceleration parameter, equation of state, and cosmological plane considering the Amended FRW modal. Modified field equations of -gravity theory gave two independent solutions. In the first case, this model provided the transitional change from deceleration to acceleration compatible with collected observational data. However, it supported a decelerating phase of expansion only in the second case. It was noted that the Equation of State advocated the dominance era under the influence of dark energy in the first case and the second predicted the influence of Λ CDM. In both cases, ω < 0 , ω ′ < 0 voted that the universe is in a freezing region and its cosmic expansion is more rapidly accelerated in the background of Chern-Simons modified gravity.

scholarly journals MODIFIED HOLOGRAPHIC RICCI DARK ENERGY MODEL AND STATEFINDER DIAGNOSIS IN FLAT UNIVERSE

2013 ◽  
Vol 22 (09) ◽  
pp. 1350056 ◽  
Author(s):  
TITUS K. MATHEW ◽  
JISHNU SURESH ◽  
DIVYA DIVAKARAN
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Dark Energy Model ◽  
Cold Dark Matter ◽  
State Parameter ◽  
Energy Model ◽  
Model Parameters ◽  
Ricci Dark Energy ◽  
Evolutionary Trajectories ◽  
Parameter Values

Evolution of the universe with modified holographic Ricci dark energy model is considered. Dependency of the equation of state parameter and deceleration parameter on the redshift and model parameters are obtained. It is shown that the density evolution of both the nonrelativistic matter and dark energy are same until recent times. The evolutionary trajectories of the model for different model parameters are obtained in the statefinder planes, r – s and r – q planes. The present statefinder parameters are obtained for different model parameter values, using that the model is differentiated from other standard models like the ΛCDM model. We have also shown that the evolutionary trajectories are depending on the model parameters, and at past times the dark energy is behaving like cold dark matter, with equation of state equal to zero.

scholarly journals f(T) GRAVITY FROM HOLOGRAPHIC RICCI DARK ENERGY MODEL WITH NEW BOUNDARY CONDITIONS

2013 ◽  
Vol 28 (39) ◽  
pp. 1350171 ◽  
Author(s):  
PENG HUANG ◽  
YONG-CHANG HUANG ◽  
FANG-FANG YUAN
Keyword(s):  
Dark Energy ◽  
Boundary Conditions ◽  
Dark Energy Model ◽  
Energy Model ◽  
Ricci Dark Energy ◽  
Expected Information ◽  
Better Than

Commonly used boundary conditions in reconstructing f(T) gravity from holographic Ricci dark energy (RDE) model are found to cause some problem, we therefore propose new boundary conditions in this paper. By reconstructing f(T) gravity from the RDE with these new boundary conditions, we show that the new ones are better than the present commonly used ones since they can give the physically expected information, which is lost when the commonly used ones are taken in the reconstruction, of the resulting f(T) theory. Thus, the new boundary conditions proposed here are more suitable for the reconstruction of f(T) gravity.

scholarly journals More on the holographic Ricci dark energy model: smoothing Rips through interaction effects?

2018 ◽  
Vol 78 (4) ◽  
Author(s):  
Mariam Bouhmadi-López ◽  
Ahmed Errahmani ◽  
Taoufik Ouali ◽  
Yaser Tavakoli
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Interaction Effects ◽  
Energy Model ◽  
Ricci Dark Energy
Sign in / Sign up

Export Citation Format

Share Document