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 Thermodynamics of the viscous f(T,B) gravity in the new agegraphic dark energy model

2020 ◽  
Vol 35 (20) ◽  
pp. 2050166 ◽  
Author(s):  
A. Pourbagher ◽  
Alireza Amani
Keyword(s):  
Dark Energy ◽  
Hubble Parameter ◽  
Dark Energy Model ◽  
Apparent Horizon ◽  
Second Law Of Thermodynamics ◽  
Energy Model ◽  
Accelerated Expansion ◽  
Agegraphic Dark Energy ◽  
New Agegraphic Dark Energy ◽  
The Universe

In this paper, we first obtain the energy density by the approach of the new agegraphic dark energy model, and then the [Formula: see text] gravity model is studied as an alternative to the dark energy in a viscous fluid by flat-FRW background, in which [Formula: see text] and [Formula: see text] are torsion scalar and boundary term. The Friedmann equations will be obtained in the framework of modified teleparallel gravity by tetrad components. We consider that the universe dominates with components such as matter and dark energy by an interacting model. The Hubble parameter is parameterized by the power-law for the scale factor, and then we fit the corresponding Hubble parameter with observational data constraints. The variation of the equation of state (EoS) for dark energy is plotted as a function of the redshift parameter, and the accelerated expansion of the universe is explored. In what follows, the stability of the model is also studied on the base of the sound speed parameter. Finally, the generalized second law of thermodynamics is investigated by entropies of inside and on the boundary of the apparent horizon in thermodynamics equilibrium.

scholarly journals Tsallis agegraphic dark energy model

2019 ◽  
Vol 34 (11) ◽  
pp. 1950086 ◽  
Author(s):  
M. Abdollahi Zadeh ◽  
A. Sheykhi ◽  
H. Moradpour
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Dark Energy Model ◽  
Late Time ◽  
Conformal Time ◽  
Classical Level ◽  
Agegraphic Dark Energy ◽  
Energy Models ◽  
Age Of The Universe ◽  
The Universe

Using the non-extensive Tsallis entropy and the holographic hypothesis, we propose a new dark energy (DE) model with timescale as infrared (IR) cutoff. Considering the age of the Universe as well as the conformal time as IR cutoffs, we investigate the cosmological consequences of the proposed DE models and study the evolution of the Universe filled by a pressureless matter and the obtained DE candidates. We find that although this model can describe the late time acceleration and the density, deceleration and the equation of state parameters show satisfactory behavior by themselves, these models are classically unstable unless the interaction between the two dark sectors of the Universe is taken into account. In addition, the results of the existence of a mutual interaction between the cosmos sectors are also addressed. We find out that the interacting models are stable at the classical level which is in contrast to the original interacting agegraphic dark energy models which are classically unstable [K. Y. Kim, H. W. Lee and Y. S. Myung, Phys. Lett. B 660, 118 (2008)].

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 INTERACTING MODEL OF NEW AGEGRAPHIC DARK ENERGY: COSMOLOGICAL EVOLUTION AND STATEFINDER DIAGNOSTIC

2010 ◽  
Vol 19 (01) ◽  
pp. 21-35 ◽  
Author(s):  
LI ZHANG ◽  
JINGLEI CUI ◽  
JINGFEI ZHANG ◽  
XIN ZHANG
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Energy Model ◽  
Cosmological Evolution ◽  
Agegraphic Dark Energy ◽  
New Agegraphic Dark Energy ◽  
Evolution Of The Universe ◽  
Energy Models ◽  
The Universe ◽  
Matter Component

The statefinder diagnostic is a useful method for distinguishing different dark energy models. In this paper, we investigate the new agegraphic dark energy model with interaction between dark energy and matter component by using statefinder parameter pair {r, s} and study its cosmological evolution. We plot the trajectories of the new agegraphic dark energy model for different interaction cases in the statefinder plane. As a result, the influence of the interaction on the evolution of the universe is shown in the statefinder diagrams.

scholarly journals A look into the cosmological consequences of a dark energy model with higher derivatives of H in the framework of Chameleon Brans–Dicke cosmology

2019 ◽  
Vol 28 (11) ◽  
pp. 1950149 ◽  
Author(s):  
Antonio Pasqua ◽  
Surajit Chattopadhyay ◽  
Aroonkumar Beesham
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Late Time ◽  
Statefinder Parameters ◽  
Eos Parameter ◽  
Higher Derivatives ◽  
De Formula ◽  
Derivatives Of ◽  
The Universe ◽  
Far Future

In this paper, we study some relevant cosmological features of a Dark Energy (DE) model with Granda–Oliveros cut-off, which is just a specific case of Nojiri–Odintsov holographic DE [S. Nojiri and S. D. Odintsov, Gen. Relativ. Gravit. 38 (2006) 1285] unifying phantom inflation with late-time acceleration, in the framework of Chameleon Brans–Dicke (BD) cosmology. Choosing a particular ansatz for some of the quantities involved, we derive the expressions of some important cosmological quantities, like the Equation of State (EoS) parameter of DE [Formula: see text], the effective EoS parameter [Formula: see text], the pressure of DE [Formula: see text] and the deceleration parameter [Formula: see text]. Moreover, we study the behavior of statefinder parameters [Formula: see text] and [Formula: see text], of the cosmographic parameters [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] and of the squared speed of the sound [Formula: see text] for both case corresponding to noninteracting and interacting Dark sectors. We also plot the quantities we have derived and we calculate their values for [Formula: see text] (i.e. for the beginning of the universe history), for [Formula: see text] (i.e. for far future) and for the present time, indicated with [Formula: see text]. The EoS parameters have been tested against various observational values available in the literature.

scholarly journals The cosmological behavior and the statefinder diagnosis for the New Tsallis agegraphic dark energy

2020 ◽  
Vol 35 (38) ◽  
pp. 2050318
Author(s):  
Umesh Kumar Sharma ◽  
Shikha Srivastava
Keyword(s):  
Dark Energy ◽  
Dynamical Analysis ◽  
Current Phase ◽  
Statefinder Parameters ◽  
Frw Universe ◽  
Eos Parameter ◽  
Agegraphic Dark Energy ◽  
Evolutionary Trajectories ◽  
The Universe ◽  
Friedmann Robertson Walker

In this work, we have considered the recently proposed new Tsallis agegraphic dark energy (NTADE) model [Mod. Phys. Lett. A 34, 1950086 (2019)] within the framework of a flat Friedmann–Robertson–Walker (FRW) Universe by taking various values of the parameter [Formula: see text]. The NTADE model shows the current phase transition of the Universe from decelerated to accelerated phase. The NTADE equation of state (EoS) parameter shows a rich behavior as it can be quintessence-like or phantom-like depending on the value of [Formula: see text]. For discriminating the NTADE model from [Formula: see text]CDM, we have plotted the statefinder parameters [Formula: see text], [Formula: see text] and [Formula: see text], [Formula: see text] pair. The NTADE model shows distinct evolutionary trajectories of their evolution in ([Formula: see text]) and ([Formula: see text]) plane. An analysis using the snap parameter and the [Formula: see text] pair dynamical analysis have also been performed.

scholarly journals LATE-TIME PHANTOM UNIVERSE IN SO(1, 1) DARK ENERGY MODEL WITH EXPONENTIAL POTENTIAL

2005 ◽  
Vol 20 (15) ◽  
pp. 1147-1154 ◽  
Author(s):  
YI-HUAN WEI
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Energy Model ◽  
Late Time ◽  
De Sitter ◽  
Exponential Potential ◽  
Coupling Energy ◽  
Expansion Phase ◽  
Perturbation Field ◽  
The Universe

We discuss the late-time property of universe and phantom field in the SO(1, 1) dark energy model for the potential V = V0e-βΦα with α and β two positive constants. We assume in advance some conditions satisfied by the late-time field to simplify equations, which are confirmed to be correct from the eventual results. For α < 2, the field falls exponentially off and the phantom equation of state rapidly approaches -1. When α = 2, the kinetic energy ρk and the coupling energy ρc become comparable but there is always ρk < -ρc so that the phantom property of field proceeds to hold. The analysis on the perturbation to the late-time field Φ illustrates the square effective mass of the perturbation field is always positive and thus the phantom is stable. The universe considered currently may evade the future sudden singularity and will evolve to de Sitter expansion phase.

Sign in / Sign up

Export Citation Format

Share Document