scholarly journals THE COSMOLOGICAL DYNAMICS OF INTERACTING HOLOGRAPHIC DARK ENERGY MODEL

2009 ◽  
Vol 18 (01) ◽  
pp. 147-157 ◽  
Author(s):  
M. R. SETARE ◽  
ELIAS C. VAGENAS
Keyword(s):  
Dark Energy ◽  
Cosmological Model ◽  
Critical Points ◽  
Dark Energy Model ◽  
Holographic Dark Energy ◽  
Cosmic Acceleration ◽  
Holographic Dark Energy Model ◽  
Evolution Of The Universe ◽  
Energy Scenario ◽  
The Universe

Motivated by the recent observations for cosmic acceleration and the suitable evolution of the universe provided an interaction (decay of dark energy to matter) is incorporated in a cosmological model, we study the cosmological evolution of the interacting holographic dark energy scenario. Critical points are derived and their corresponding cosmological models are presented. The dynamical character of these models is revealed.

scholarly journals PRESENT ACCELERATION OF THE UNIVERSE, HOLOGRAPHIC ENERGY AND BRANS–DICKE THEORY

2009 ◽  
Vol 24 (22) ◽  
pp. 1785-1792 ◽  
Author(s):  
B. NAYAK ◽  
L. P. SINGH
Keyword(s):  
Dark Energy ◽  
Power Law ◽  
Dark Energy Model ◽  
Holographic Dark Energy ◽  
Accelerated Expansion ◽  
Temporal Behavior ◽  
Holographic Dark Energy Model ◽  
Acceleration Of The Universe ◽  
Expansion Of The Universe ◽  
The Universe

The present-day accelerated expansion of the universe is naturally addressed within the Brans–Dicke theory just by using holographic dark energy model with inverse of Hubble scale as IR cutoff and power law temporal behavior of scale factor. It is also concluded that if the universe continues to expand, then one day it might be completely filled with dark energy.

Reconstructing Tsallis holographic quintessence

2021 ◽  
Author(s):  
Umesh Kumar Sharma ◽  
Vandna Srivastava
Keyword(s):  
Dark Energy ◽  
Scalar Field ◽  
Quantum Gravity ◽  
Dark Energy Model ◽  
Holographic Dark Energy ◽  
Energy Model ◽  
Holographic Dark Energy Model ◽  
The Universe ◽  
Modified Entropy

Within the framework of quantum gravity and modified entropy-area formalism, the Tsallis holographic dark energy is an effort to peep into a mysterious content of the Universe, the dark energy, to analyze its nature. The Tsallis parameter [Formula: see text] provides the main characteristic of the Tsallis holographic dark energy. Opting the value of Tsallis parameter [Formula: see text], a quintessence scalar field description of the Tsallis holographic dark energy model can be obtained. In this work, we present this quintessential explanation of the Tsallis holographic dark energy with [Formula: see text] and reconstruct the dynamics of the scalar field and the potential of quintessence.

scholarly journals DARK ENERGY AND THE FUTURE FATE OF THE UNIVERSE

2007 ◽  
Vol 22 (35) ◽  
pp. 2689-2699
Author(s):  
YUNGUI GONG ◽  
YUAN-ZHONG ZHANG
Keyword(s):  
Dark Energy ◽  
Event Horizon ◽  
Dark Energy Model ◽  
Holographic Dark Energy ◽  
Scale Factor ◽  
Energy Model ◽  
Holographic Dark Energy Model ◽  
Hubble Horizon ◽  
Size Criterion ◽  
The Universe

We consider the possibility of observing the onset of the late time inflation of our patch of the Universe. The Hubble size criterion and the event horizon criterion are applied to several dark energy models to discuss the problem of future inflation of the Universe. We find that the acceleration has not lasted long enough to confirm the onset of inflation by present observations for the dark energy model with constant equation of state, the holographic dark energy model and the generalized Chaplygin gas (GCG) model. For the flat ΛCDM model with Ωm0 = 0.3, we find that if we use the Hubble size criterion, we need to wait until the av which is the scale factor at the time when the onset of inflation is observed reaches 3.59 times of the scale factor aT when the Universe started acceleration, and we need to wait until av = 2.3aT to see the onset of inflation if we use the event horizon criterion. For the flat holographic dark energy model with d = 1, we find that av = 3.46aT with the Hubble horizon and av = 2.34aT with the event horizon, respectively. For the flat GCG model with the best supernova fitting parameter α = 1.2, we find that av = 5.50aT with the Hubble horizon and av = 2.08aT with the event horizon, respectively.

scholarly journals Tsallis Holographic Dark Energy with Granda-Oliveros Scale in (n+1)-Dimensional FRW Universe

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Ayman A. Aly
Keyword(s):  
Dark Energy ◽  
Speed Of Sound ◽  
Dark Energy Model ◽  
Holographic Dark Energy ◽  
Holographic Dark Energy Model ◽  
Frw Universe ◽  
Accelerating Expansion ◽  
The Stability ◽  
The Universe ◽  
Friedmann Robertson Walker

Based on Tsallis holographic dark energy model recently proposed by using the general model of the Tsallis entropy expression, we reconstruct cosmographic parameters, q,j,κ,l, and we study their evolution in spatially flat (n+1)-dimensional Friedmann-Robertson-Walker universe using Granda-Oliveros scale. Our results show that the universe is in an accelerating expansion mode described by phantom-like behavior. We go further and study the state finder operators and the Om diagnostic to understand the behavior of our model. The stability of the system is also studied by using the square of speed of sound showing that our model is stable over the low range of red-shift considered. The results indicate that the entropy formalism will play an important role in understanding the dynamics of our universe.

Bianchi type-III holographic dark energy model with quintessence

2018 ◽  
Vol 15 (09) ◽  
pp. 1850161 ◽  
Author(s):  
M. Vijaya Santhi ◽  
V. U. M. Rao ◽  
Daba Meshesha Gusu ◽  
Y. Aditya
Keyword(s):  
Dark Energy ◽  
Scalar Field ◽  
Equation Of State ◽  
Dark Energy Model ◽  
Bianchi Type ◽  
Holographic Dark Energy ◽  
Scale Factor ◽  
Holographic Dark Energy Model ◽  
The Universe ◽  
Average Scale Factor

In this study, we investigate an anisotropic Bianchi type-[Formula: see text] space-time in the presence of matter and holographic dark energy components within the framework of general relativity. We obtained the solution of the field equations by assuming (i) the expansion scalar [Formula: see text] in the model is proportional to shear scalar [Formula: see text], (ii) hybrid expansion law for average scale factor (keeping an eye on the recent scenario of accelerating nature of the universe). We develop cosmological parameters like deceleration and equation of state parameters. These parameters are plotted versus redshift [Formula: see text] for different values of power component of average scale factor [Formula: see text]. We observe that the equation of state varies in quintessence region ([Formula: see text]) and ultimately tends to [Formula: see text]CDM model ([Formula: see text]). The deceleration parameter exhibits a smooth transition from early decelerated epoch to present accelerated era. In addition, we establish the correspondence between our holographic dark energy model and quintessence scalar field. We also express the self-interacting potential [Formula: see text] and scalar field [Formula: see text] of quintessence model as functions of cosmic time [Formula: see text], which describes the accelerated expansion of the universe.

Interacting new holographic dark energy model with varying G in nonflat universe

2013 ◽  
Vol 91 (12) ◽  
pp. 1090-1092
Author(s):  
V. Fayaz ◽  
F. Felegary ◽  
H. Hossienkhani
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Dark Energy Model ◽  
Holographic Dark Energy ◽  
Energy Model ◽  
Accelerated Expansion ◽  
Late Time ◽  
Holographic Dark Energy Model ◽  
Expansion Of The Universe ◽  
The Universe

Motivated by the work of Karami and Fehri (Phys. Lett. B, 684, 61 (2010)). We generalize their work with varying G. We investigate the new holographic dark energy model with varying G. We consider a spatially nonflat universe containing interacting new holographic dark energy with pressureless dark matter. We obtain the equation of state and the deceleration parameters. Also we reconstruct ωA for a = a0tn and H = [β/(α − 1)](1/t) in the late time universe. We also obtain q for a = a0tn and H = [β/(α − 1)](1/t) in the present time universe, which describes accelerated expansion of the universe.

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