scholarly journals Interacting Quintessence Dark Energy Models in Lyra Manifold

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
M. Khurshudyan ◽  
J. Sadeghi ◽  
R. Myrzakulov ◽  
Antonio Pasqua ◽  
H. Farahani
Keyword(s):  
Dark Energy ◽  
Numerical Analysis ◽  
Cosmological Parameters ◽  
Chaplygin Gas ◽  
Modified Chaplygin Gas ◽  
Van Der Waals Gas ◽  
Lyra Manifold ◽  
Energy Models ◽  
Two Component ◽  
Quintessence Field

We consider two-component dark energy models in Lyra manifold. The first component is assumed to be a quintessence field while the second component may be a viscous polytropic gas, a viscous Van der Waals gas, or a viscous modified Chaplygin gas. We also consider the possibility of interaction between components. By using the numerical analysis, we study some cosmological parameters of the models and compare them with observational data.

THE MODIFIED CHAPLYGIN GAS AS A UNIFIED DARK SECTOR MODEL

2007 ◽  
Vol 22 (11) ◽  
pp. 783-790 ◽  
Author(s):  
YABO WU ◽  
SONG LI ◽  
JIANBO LU ◽  
XIUYI YANG
Keyword(s):  
Dark Energy ◽  
State Parameter ◽  
Chaplygin Gas ◽  
Modified Chaplygin Gas ◽  
Dark Sector ◽  
Phantom Divide ◽  
Sector Model ◽  
Energy Models ◽  
Big Rip ◽  
The Future

A modified Chaplygin gas (MCG) model of unifying dark energy and dark matter is considered in this paper. Concretely, the evolution of such a unified dark sector model is studied and the statefinder diagnostic to the MCG model is performed in our model. By analysis, it is shown that the state parameter of dark energy can cross the so-called phantom divide ω = -1, the behavior of MCG will be like ΛCDM in the future and therefore our universe will not end up with Big Rip in the future. In addition, we plot the evolution trajectory of the MCG model in the statefinder parameter r–s plane and show the discrimination between this scenario and other dark energy models.

scholarly journals Stability and interacting f(T, T ) gravity with modified Chaplygin gas

2017 ◽  
Vol 95 (11) ◽  
pp. 1068-1073 ◽  
Author(s):  
T. Mirzaei Rezaei ◽  
Alireza Amani
Keyword(s):  
Dark Energy ◽  
Cosmological Parameters ◽  
Teleparallel Gravity ◽  
Chaplygin Gas ◽  
Accelerated Expansion ◽  
Phase Plane Analysis ◽  
Modified Chaplygin Gas ◽  
Continuity Equations ◽  
The Stability ◽  
The Universe

In this paper, the model of interaction is studied between f(T, [Formula: see text]) gravity and modified Chaplygin gas in Friedmann–Robertson–Walker (FRW)-flat metric. We obtain the Friedmann equations in the framework of teleparallel gravity by vierbein field. We consider that the Universe is dominated by components of cold matter, dark energy, and modified Chaplygin gas. In what follows we separately write the corresponding continuity equations for components of the Universe. Also, dark energy equation of state (EoS) and effective EoS are obtained with respect to redshift, thereinafter the corresponding cosmological parameters are plotted in terms of redshift, thereinafter the accelerated expansion of the Universe is investigated. Finally, the stability of the model is discussed in phase plane analysis.

A VARIABLE MODIFIED CHAPLYGIN GAS MODEL WITH INTERACTION

2009 ◽  
Vol 18 (12) ◽  
pp. 1851-1862 ◽  
Author(s):  
LILI XING ◽  
YUANXING GUI ◽  
CHUNYAN WANG
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
State Parameter ◽  
Chaplygin Gas ◽  
Modified Chaplygin Gas ◽  
Phantom Divide ◽  
Energy Models ◽  
Big Rip ◽  
Variable Modified Chaplygin Gas ◽  
The Future

We consider in this paper a variable modified Chaplygin gas (VMCG) model for describing the unification of dark energy and dark matter, in which dark energy interacts with dark matter. Concretely, the evolution of the VMCG model with interaction is discussed and the statefinder diagnostic for the model is performed. By analysis, we find that the effective state parameter of dark energy can cross the phantom divide wΛ= -1 and our universe will not end up with a Big Rip in the future. Furthermore, we perform a statefinder analysis on this scenario and show the discrimination between this scenario and other dark energy models.

scholarly journals Interacting models of generalized Chaplygin gas and modified Chaplygin gas with barotropic fluid

2019 ◽  
Vol 34 (09) ◽  
pp. 1950064 ◽  
Author(s):  
Promila Biswas ◽  
Ritabrata Biswas
Keyword(s):  
Dark Energy ◽  
Energy Density ◽  
Cosmological Parameters ◽  
Chaplygin Gas ◽  
Cosmic Acceleration ◽  
Late Time ◽  
Modified Chaplygin Gas ◽  
Interaction Coefficients ◽  
Generalized Chaplygin Gas ◽  
Barotropic Fluid

In this paper, we consider two different models of our present universe. We choose the models which consist of different sets of two separate fluids. The first one of each set tries to justify the late time acceleration and the second one is barotropic fluid. The former model considers our present time universe to be homogeneously filled up by Generalized Chaplygin Gas which is interacting with barotropic fluid. On the other hand, the latter model considers that the cosmic acceleration is generated by Modified Chaplygin Gas which is interacting with matter depicted by barotropic equation of state (EoS). For both the models, we consider the interaction term to vary proportionally with Hubble’s parameter as well as with the exotic matter/dark energy’s energy density. We find an explicit function form of the energy density of the cosmos which is found to depend on different cosmological parameters like scale factor, dark energy and barotropic fluid’s EoS parameters and other constants, like interacting constants, etc. We draw curves of effective EoS-s, different cosmological parameters like deceleration parameter q, statefinder parameters r and s with respect to the redshift z (for different values of dark energy and barotropic fluid parameters) and study them thoroughly. We compare two models as well as the nature of dependencies on these models’ interaction coefficients. We point out the particular redshift for which the universe may transit from a deceleration to acceleration phase. We tally all these values with different observational data. Here, we also analyze how this value of particular redshift does change for different values of interaction coefficients and different dark energy models.

Entropy-corrected new agegraphic dark energy model in the context of Chern–Simons modified gravity

2015 ◽  
Vol 24 (06) ◽  
pp. 1550044
Author(s):  
Ayman A. Aly ◽  
M. Fekry ◽  
H. Mansour
Keyword(s):  
Dark Energy ◽  
Modified Gravity ◽  
Generalized Uncertainty Principle ◽  
Chaplygin Gas ◽  
Modified Chaplygin Gas ◽  
Agegraphic Dark Energy ◽  
New Agegraphic Dark Energy ◽  
Energy Models ◽  
Cs Modified Gravity ◽  
Chern Simons

Within the framework of Chern–Simons (CS) modified gravity, we studied dark energy models. The new agegraphic dark energy (NADE) model, entropy-corrected new agegraphic dark energy (ECNADE) model and NADE model with generalized uncertainty principle (GUP) are investigated. For these models, we studied the evolution of scale factor a, Hubble parameter H and deceleration parameter q. On meantime, we studied the state finder parameters s and r. These models show some similar behavior with modified Chaplygin gas model in some regions, while in other regions some similarity with phantom and quintessence dark energy is noticed.

scholarly journals Interacting F(R, T) gravity with modified Chaplygin gas

2015 ◽  
Vol 93 (12) ◽  
pp. 1453-1459 ◽  
Author(s):  
Ali R. Amani ◽  
S.L. Dehneshin
Keyword(s):  
Dark Energy ◽  
Sound Speed ◽  
Cosmological Parameters ◽  
Field Potential ◽  
Chaplygin Gas ◽  
Accelerated Expansion ◽  
Late Time ◽  
Modified Chaplygin Gas ◽  
Curvature And Torsion ◽  
The Universe

In this paper, we have studied F(R, T) gravity as an arbitrary function of curvature and torsion scalars in Friedmann–Lemaître–Robertson–Walker background. Then, we have considered interacting model between F(R, T) gravity and modified Chaplygin gas. The novelty of this model is that the Universe includes both curvature and torsion cases, and one dominated by a Chaplygin gas. To calculate cosmological solutions, we obtained the Friedmann equations and also equation of state parameter of dark energy. By employing the interacting model we considered the total energy density and the total pressure of the Universe as the combination of components of dark energy and Chaplygin gas. Subsequently, we reconstructed the model by an origin of a scalar field entitled quintessence model with a field potential. The field potential has been calculated in terms of free parameters of F(R, T) gravity and modified Chaplygin gas. In what follows, we used a parametrization, and the cosmological parameters have been written in terms of redshift z. Next, we plotted cosmological parameters with respect to three variables: cosmic time, redshift z, and e-folding number N = ln(a), and the figures showed us an accelerated expansion of the Universe. Also, we have described the scenario in three statuses: early time, late time, and future time, by e-folding number. Finally, the stability of the scenario has been investigated using sound speed, and the graph of sound speed versus e-folding number has shown us that there is stability in late time.

scholarly journals Late Time Attractors of Some Varying Chaplygin Gas Cosmological Models

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 769
Author(s):  
Martiros Khurshudyan ◽  
Ratbay Myrzakulov
Keyword(s):  
Dark Energy ◽  
Gravitational Interaction ◽  
Chaplygin Gas ◽  
Cosmological Models ◽  
Late Time ◽  
Time Behavior ◽  
Coincidence Problem ◽  
Energy Models ◽  
Non Linear ◽  
Bayesian Machine Learning

The goal of this paper is to study new cosmological models where the dark energy is a varying Chaplygin gas. This specific dark energy model with non-linear EoS had been often discussed in modern cosmology. Contrary to previous studies, we consider new forms of non-linear non-gravitational interaction between dark matter and assumed dark energy models. We applied the phase space analysis allowing understanding the late time behavior of the models. It allows demonstrating that considered non-gravitational interactions can solve the cosmological coincidence problem. On the other hand, we applied Bayesian Machine Learning technique to learn the constraints on the free parameters. In this way, we gained a better understanding of the models providing a hint which of them can be ruled out. Moreover, the learning based on the simulated expansion rate data shows that the models cannot solve the H0 tension problem.

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.

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