Interacting ω(q) dark energy model with phase space analysis

2021 ◽  
Vol 36 (31) ◽  
Author(s):  
Koblandy Yerzhanov ◽  
Shynaray Myrzakul ◽  
Duman Kenzhalin ◽  
Martiros Khurshudyan

The phase space analysis has been used to probe the accelerated expansion of the Universe when [Formula: see text] dark energy interacts with cold dark matter. Non-gravitational interactions [Formula: see text] and [Formula: see text] considered in this work are one of the first models of sign changing interactions that appeared in the literature. Specific [Formula: see text] dark energy model with [Formula: see text] has been assumed and all late time scaling attractors have been found. This is a two-parameter model with [Formula: see text] and [Formula: see text] parameters to be determined, while [Formula: see text] is the deceleration parameter. In general the motivation to consider similar fluid models is directly related to the attempts to unify dark energy and dark matter involving the properties of the deceleration parameter. The previous study using similar dark energy model showed that the BOSS result for the expansion rate at [Formula: see text] can be explained without interaction with cold dark matter. In this way, the previous result provides a reasonable basis to organize future studies in this direction. This study is one of the first attempts in this direction. It should be mentioned that the full comparison of the models with observation data and the classification of future singularities have been left as a subject of a forthcoming paper. There are several ways that the model can be extended which also has been left as a subject of a forthcoming paper.

2005 ◽  
Vol 628 (1-2) ◽  
pp. 1-10 ◽  
Author(s):  
I.Ya. Aref'eva ◽  
A.S. Koshelev ◽  
S.Yu. Vernov

2016 ◽  
Vol 2016 ◽  
pp. 1-20 ◽  
Author(s):  
Emre Dil

We propose a novel coupled dark energy model which is assumed to occur as aq-deformed scalar field and investigate whether it will provide an expanding universe phase. We consider theq-deformed dark energy as coupled to dark matter inhomogeneities. We perform the phase-space analysis of the model by numerical methods and find the late-time accelerated attractor solutions. The attractor solutions imply that the coupledq-deformed dark energy model is consistent with the conventional dark energy models satisfying an acceleration phase of universe. At the end, we compare the cosmological parameters of deformed and standard dark energy models and interpret the implications.


2016 ◽  
Vol 25 (14) ◽  
pp. 1650104 ◽  
Author(s):  
F. Darabi ◽  
F. Felegary ◽  
M. R. Setare

We investigate the cosmological dynamics of interacting Logarithmic Entropy Corrected Holographic Dark Energy model with Cold Dark Matter. Fixed points are determined and their corresponding cosmological models are presented. Moreover, the dynamical properties of these fixed points are derived.


2016 ◽  
Vol 31 (24) ◽  
pp. 1650137
Author(s):  
Martiros Khurshudyan

In this paper, we organize a look to nonlinear interacting Ghost dark energy cosmology involving a discussion on the thermodynamics of the Ghost dark energy, when the universe is bounded via the Hubble horizon. One of the ways to study a dark energy model, is to reconstruct thermodynamics of it. Ghost dark energy is one of the models of the dark energy which has an explicitly given energy density as a function of the Hubble parameter. There is an active discussion towards various cosmological scenarios, where the Ghost dark energy interacts with the pressureless cold dark matter (CDM). Recently, various models of the varying Ghost dark energy has been suggested, too. To have a comprehensive understanding of suggested models, we will discuss behavior of the cosmological parameters on parameter-redshift [Formula: see text] plane. Some discussion on Om and statefinder hierarchy analysis of these models is presented. Moreover, up to our knowledge, suggested forms of interaction between the Ghost dark energy and cold dark matter (CDM) are new, therefore, within obtained results, we provide new contribution to previously discussed models available in the literature. Our study demonstrates that the forms of the interactions considered in the Ghost dark energy cosmology are not exotic and the justification of this is due to the recent observational data.


2017 ◽  
Vol 26 (03) ◽  
pp. 1750015 ◽  
Author(s):  
Orlando Luongo ◽  
Giovanni Battista Pisani ◽  
Antonio Troisi

In this work, we use cosmography to alleviate the degeneracy among cosmological models, proposing a way to parametrize matter and dark energy in terms of cosmokinematics quantities. The recipe of using cosmography allows to expand observable quantities in Taylor series and to directly compare those expansions with data. The strategy involves the expansions of [Formula: see text] and [Formula: see text], up to the second-order around [Formula: see text]. This includes additional cosmographic parameters which are fixed by current values of [Formula: see text] and [Formula: see text]. We therefore propose a fully self-consistent parametrization of the total energy density driving the late-time universe speed up. This stratagem does not remove all the degeneracy but enables one to pass from the model-dependent couple of coefficients, [Formula: see text] and [Formula: see text], to model-independent quantities determined from cosmography. Afterwards, we describe a feasible cosmographic dark energy model, in which matter is fixed whereas dark energy evolves by means of the cosmographic series. Our technique provides robust constraints on cosmokinematic parameters, permitting one to separately bound matter from dark energy densities. Our cosmographic dark energy model turns out to be one parameter only, but differently from the lambda cold dark matter ([Formula: see text]CDM) paradigm, it does not contain ansatz on the dark energy form. In addition, we even determine the free parameter of our model in suitable [Formula: see text] intervals through Monte Carlo analyses based on the Metropolis algorithm. We compare our results with the standard concordance model and we find that our treatment seems to indicate that dark energy slightly evolves in time, reducing to a pure cosmological constant only as [Formula: see text].


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