Anisotropic cosmological models in f(R,T) gravity according to holographic and new agegraphic dark energy

2014 ◽  
Vol 353 (2) ◽  
pp. 301-309 ◽  
Author(s):  
V. Fayaz ◽  
H. Hossienkhani ◽  
M. Amirabadi ◽  
N. Azimi
2020 ◽  
Vol 35 (28) ◽  
pp. 2050175
Author(s):  
Sayani Maity ◽  
Mahasweta Biswas ◽  
Ujjal Debnath

This work deals with two fluid system in the framework of generalized Rastall gravity theory. One component represents dark energy whereas the other is dark matter. For the dark energy component, entropy corrected holographic and entropy corrected new agegraphic dark energy models in power-law and logarithmic versions are taken into account. For this study, we assume two classes of scale factors in which one corresponds to the future singularity and another corresponds to the initial singularity. For each of the entropy corrected dark energy models, the cosmological parameters such as Hubble parameter, deceleration parameter and equation of state parameter are calculated and their implications are established. Furthermore, to describe the stability analysis of the models, the behaviors of the squared speed of sound are analyzed graphically for each of these models. From the graphical analysis of [Formula: see text] plane, the thawing or freezing regions of all the models are determined.


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.


2011 ◽  
Vol 26 (10) ◽  
pp. 727-737 ◽  
Author(s):  
LEI WANG ◽  
YA-BO WU ◽  
LEI LI ◽  
YUAN GAO ◽  
JIAN GAO

In this paper, motivated by Ref. 31, we study the so-called new agegraphic Chaplygin gas model with viscosity. Concretely, we establish the correspondence between the interacting new agegraphic dark energy (NADE) and variable generalized Chaplygin gas (VGCG) models in non-flat universe on the basis of reviewing related contents for the NADE and VGCG models. Furthermore, we reconstruct the potential of the new agegraphic scalar field as well as the dynamics of the scalar field according to the evolution of the agegraphic dark energy. Finally, we generalize our study to the case of NADE with viscosity, which includes the case without viscosity (ν = 0) as a special case.


2011 ◽  
Vol 50 (10) ◽  
pp. 3069-3077 ◽  
Author(s):  
Mubasher Jamil ◽  
K. Karami ◽  
A. Sheykhi

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.


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