ATTRACTOR BEHAVIOR IN DILATONIC (PHANTOM) DARK ENERGY MODEL WITH POTENTIAL [1+(σ-A)2]e-Bσ

2006 ◽  
Vol 21 (39) ◽  
pp. 2977-2987
Author(s):  
Z. G. HUANG ◽  
H. Q. LU ◽  
W. FANG
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Energy Model ◽  
Fine Tuning ◽  
Density Parameter ◽  
Dilaton Field ◽  
Phantom Model ◽  
Attractor Solution ◽  
Phantom Dark Energy ◽  
M Theory

In this paper, we consider the dilatonic dark energy model and its phantom model. Based on the dilatonic (phantom) model, we take the potential of dilaton field of the form [1+(σ-A)2]e-Bσ which seems to connect with ideas from M-theory, and analyze the sufficient condition for the existence of attractor solution. We find that the behavior of the attractor is not sensitive to the initial condition, thus the fine-tuning problem is alleviated. By numerical analysis, we investigate the asymptotic behavior of the attractor, which corresponds to an equation of state ω = -1 and a cosmic density parameter Ωσ = 1.

COSMOLOGICAL DYNAMICS OF DILATONIC (PHANTOM) DARK ENERGY MODEL

2006 ◽  
Vol 15 (09) ◽  
pp. 1501-1514 ◽  
Author(s):  
Z. G. HUANG ◽  
H. Q. LU
Keyword(s):  
Dark Energy ◽  
Kinetic Energy ◽  
Dark Energy Model ◽  
Energy Model ◽  
Density Parameter ◽  
Late Time ◽  
Sufficient Condition ◽  
Phantom Model ◽  
Attractor Solution ◽  
Phantom Dark Energy

In this paper, we study the cosmological dynamics of dilatonic dark energy model and its phantom model — with negative kinetic energy. When the potential is taken as the form [Formula: see text], we investigate the existence of a late time attractor solution, and find out the sufficient condition. One interesting feature found by us is that the evolutions of components of comic density are locally fluctuating on the way to the late time attractor. But this local fluctuation cannot hold the trend that the equation of state ω evolves to -1 and the cosmic density parameter Ωσ evolves to 1, which are important features for a dark energy model that can meet the current observations.

Exact solution of phantom dark energy model

2010 ◽  
Vol 19 (11) ◽  
pp. 119801 ◽  
Author(s):  
Wen-Fu Wang ◽  
Zheng-Wei Shui ◽  
Bin Tang
Keyword(s):  
Exact Solution ◽  
Dark Energy ◽  
Dark Energy Model ◽  
Energy Model ◽  
Phantom Dark Energy

scholarly journals Parametrization of Born-Infeld type phantom dark energy model

2009 ◽  
Vol 324 (1) ◽  
pp. 55-59
Author(s):  
Z. G. Huang ◽  
H. Q. Lu ◽  
W. Fang
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Energy Model ◽  
Phantom Dark Energy

STATEFINDER PARAMETERS FOR PHANTOM DARK ENERGY

2006 ◽  
Vol 21 (16) ◽  
pp. 1305-1311 ◽  
Author(s):  
PUXUN WU ◽  
HONGWEI YU
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Energy Model ◽  
Field Potentials ◽  
Statefinder Parameters ◽  
Phantom Field ◽  
Energy Models ◽  
Phantom Dark Energy ◽  
The Universe

The statefinder parameters were introduced recently to differentiate different dark energy models. In this paper we perform a statefinder diagnostic to the phantom dark energy model with two different phantom field potentials. Our results show that the statefinder diagnostic is rather robust in differentiating not only different dark energy models but also the same kind of models with different potentials which lead to different fate of the universe.

scholarly journals CONSTRAINTS ON THAWING SCALAR FIELD MODELS FROM FUNDAMENTAL CONSTANTS

2013 ◽  
Vol 22 (07) ◽  
pp. 1350035 ◽  
Author(s):  
QING GAO ◽  
YUNGUI GONG
Keyword(s):  
Fine Structure ◽  
Dark Energy ◽  
Scalar Field ◽  
Observational Data ◽  
Dark Energy Model ◽  
Structure Constant ◽  
Energy Model ◽  
Fine Structure Constant ◽  
Density Parameter ◽  
Scalar Field Models

We consider a dark energy model with a relation between the equation of state parameter w and the energy density parameter Ωϕ derived from thawing scalar field models. Assuming the variation of the fine structure constant is caused by dark energy, we use the observational data of the variation of the fine structure constant to constrain the current value of w0 and Ωϕ0 for the dark energy model. At the 1σ level, the observational data excluded some areas around w0 = –1, which explains the positive detection of the variation of the fine structure constant at the 1σ level, but ΛCDM model is consistent with the data at the 2σ level.

scholarly journals Evolution of non-flat cosmos via GGPDE f(R) model

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
Wajiha Javed ◽  
Iqra Nawazish ◽  
Fatima Shahid ◽  
Nimra Irshad
Keyword(s):  
Dark Energy ◽  
Power Law ◽  
Dark Energy Model ◽  
Cosmological Parameters ◽  
State Parameter ◽  
Scale Factor ◽  
Energy Model ◽  
Density Parameter ◽  
Shift Parameter ◽  
Scale Factors

Abstract This paper is devoted to explore the cosmic evolution of non-flat Friedmann Robertson Walker universe through generalized ghost pilgrim dark energy model in the background of f(R) gravity. For this purpose, we consider two well known scale factors, i.e., power-law and unified scale factors in terms of red shift parameter. For these scale factors, we reconstruct the given dark energy model in f(R) gravity and determine its stability/instability through squared speed of sound parameter. In order to discuss the behavior of reconstructed and dark energy models, we evaluate well known cosmological parameter such as equation of state parameter along with $$\omega $$ω–$$\omega '$$ω′ plane. In addition to this, we also investigate compatibility of new models with standard cosmological models through state-finder parameters. The density parameter is formulated for both ordinary matter as well as dark energy components and results are compared with Planck 2018 constraints. It is concluded that cosmological parameters reveal consistency with recent observations while the value of density parameter suggested by Planck 2018 is achieved by power-law scale factor in most of the cases as compared to unified scale factor.

Statefinder diagnosis for Tsallis agegraphic dark energy model with ωD − ωD′ pair

2020 ◽  
Vol 35 (06) ◽  
pp. 2050027 ◽  
Author(s):  
Shikha Srivastava ◽  
Vipin Chandra Dubey ◽  
Umesh Kumar Sharma
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Energy Model ◽  
Density Parameter ◽  
Statefinder Parameters ◽  
Agegraphic Dark Energy ◽  
New Class ◽  
Nonextensive Entropy ◽  
Age Of The Universe ◽  
The Universe

A new class of dark energy model, known as “Tsallis agegraphic dark energy (TADE),” has been proposed using the holographic principle and Tsallis nonextensive entropy (Mod. Phys. Lett. A, 2019), considering the conformal time as well as the age of the Universe as IR cutoffs in flat Universe. The trajectories for evolution of statefinder parameters in [Formula: see text], [Formula: see text], [Formula: see text] and the [Formula: see text] planes are plotted for the TADE 1 and TADE 2 models for the value of the Tsallis parameter [Formula: see text], and taking the TADE energy density parameter [Formula: see text], according to the Planck 2018 results VI — [Formula: see text]CDM observational data without interaction.

scholarly journals Constraints on Non-Flat Starobinsky f(R) Dark Energy Model

Entropy ◽  
2021 ◽  
Vol 23 (10) ◽  
pp. 1320
Author(s):  
Chao-Qiang Geng ◽  
Yan-Ting Hsu ◽  
Jhih-Rong Lu
Keyword(s):  
Dark Energy ◽  
Observational Data ◽  
Gravity Model ◽  
Dark Energy Model ◽  
Free Parameter ◽  
Energy Model ◽  
Density Parameter ◽  
Model Parameter ◽  
Best Fitting ◽  
Characteristic Curvature

We study the viable Starobinsky f(R) dark energy model in spatially non-flat FLRW backgrounds, where f(R)=R−λRch[1−(1+R2/Rch2)−1] with Rch and λ representing the characteristic curvature scale and model parameter, respectively. We modify CAMB and CosmoMC packages with the recent observational data to constrain Starobinsky f(R) gravity and the density parameter of curvature ΩK. In particular, we find the model and density parameters to be λ−1<0.283 at 68% C.L and ΩK=−0.00099−0.0042+0.0044 at 95% C.L, respectively. The best χ2 fitting result shows that χf(R)2≲χΛCDM2, indicating that the viable f(R) gravity model is consistent with ΛCDM when ΩK is set as a free parameter. We also evaluate the values of AIC, BIC and DIC for the best fitting results of f(R) and ΛCDM models in the non-flat universe.

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