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

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.

2020 ◽  
Vol 35 (20) ◽  
pp. 2050166 ◽  
Author(s):  
A. Pourbagher ◽  
Alireza Amani

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.


2008 ◽  
Vol 23 (17n20) ◽  
pp. 1366-1371 ◽  
Author(s):  
H. W. LEE ◽  
K. Y. KIM ◽  
Y. S. MYUNG

We investigate the cosmological evolution of the new-agegraphic dark energy model which was recently proposed to explain the dark energy-dominated universe. For this purpose, we derived differential equations for density parameters and solved them numerically. We found that there exist a critical value for undetermined parameter of new-agegraphic density to obtain a stable and accessible evolution in the far past. Furthermore, this parameter seems to be fixed as the critical value for consistence.


2019 ◽  
Vol 34 (11) ◽  
pp. 1950086 ◽  
Author(s):  
M. Abdollahi Zadeh ◽  
A. Sheykhi ◽  
H. Moradpour

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)].


2006 ◽  
Vol 21 (16) ◽  
pp. 1305-1311 ◽  
Author(s):  
PUXUN WU ◽  
HONGWEI YU

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.


2021 ◽  
Vol 13 (3) ◽  
pp. 779-784
Author(s):  
P. Das ◽  
K. P. Singh

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.


2020 ◽  
Vol 35 (06) ◽  
pp. 2050027 ◽  
Author(s):  
Shikha Srivastava ◽  
Vipin Chandra Dubey ◽  
Umesh Kumar Sharma

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.


2008 ◽  
Vol 23 (36) ◽  
pp. 3049-3055 ◽  
Author(s):  
YONG-WAN KIM ◽  
HYUNG WON LEE ◽  
YUN SOO MYUNG ◽  
MU-IN PARK

We investigate the new agegraphic dark energy models with generalized uncertainty principle (GUP). It turns out that although the GUP affects the early universe, it does not change the current and future dark energy-dominated universe significantly. Furthermore, this model could describe the matter-dominated universe in the past only when the parameter n is chosen to be n > n c , where the critical value is determined to be n c = 2.799531478.


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