Stringy dark energy model with cold dark matter

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

scholarly journals Cosmological dynamics of interacting logarithmic entropy corrected holographic dark energy model

2016 ◽  
Vol 25 (14) ◽  
pp. 1650104 ◽  
Author(s):  
F. Darabi ◽  
F. Felegary ◽  
M. R. Setare
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Fixed Points ◽  
Dark Energy Model ◽  
Cold Dark Matter ◽  
Holographic Dark Energy ◽  
Energy Model ◽  
Cosmological Models ◽  
Holographic Dark Energy Model ◽  
Dynamical Properties

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.

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

2021 ◽  
Vol 36 (31) ◽  
Author(s):  
Koblandy Yerzhanov ◽  
Shynaray Myrzakul ◽  
Duman Kenzhalin ◽  
Martiros Khurshudyan
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Phase Space ◽  
Deceleration Parameter ◽  
Dark Energy Model ◽  
Cold Dark Matter ◽  
Forthcoming Paper ◽  
Energy Model ◽  
Phase Space Analysis ◽  
Space Analysis

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.

A look to nonlinear interacting Ghost dark energy cosmology

2016 ◽  
Vol 31 (24) ◽  
pp. 1650137
Author(s):  
Martiros Khurshudyan
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Dark Energy Model ◽  
Cold Dark Matter ◽  
Cosmological Parameters ◽  
Comprehensive Understanding ◽  
Ghost Dark Energy ◽  
Hierarchy Analysis ◽  
Hubble Horizon ◽  
The Universe

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.

scholarly journals Cosmological degeneracy versus cosmography: A cosmographic dark energy model

2017 ◽  
Vol 26 (03) ◽  
pp. 1750015 ◽  
Author(s):  
Orlando Luongo ◽  
Giovanni Battista Pisani ◽  
Antonio Troisi
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Free Parameter ◽  
Cold Dark Matter ◽  
Energy Model ◽  
Late Time ◽  
Total Energy Density ◽  
Self Consistent ◽  
Speed Up ◽  
Model Independent

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].

scholarly journals Dynamics of Generalized Tachyon Field in Teleparallel Gravity

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Behnaz Fazlpour ◽  
Ali Banijamali
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Scalar Field ◽  
Dark Energy Model ◽  
Teleparallel Gravity ◽  
Energy Model ◽  
Tachyon Field ◽  
Coincidence Problem

We study dynamics of generalized tachyon scalar field in the framework of teleparallel gravity. This model is an extension of tachyonic teleparallel dark energy model which has been proposed by Banijamali and Fazlpour (2012). In contrast with tachyonic teleparallel dark energy model that has no scaling attractors, here we find some scaling attractors which means that the cosmological coincidence problem can be alleviated. Scaling attractors are presented for both interacting and noninteracting dark energy and dark matter cases.

scholarly journals Model Independent Diagnostics in Interacting Dark Energy Models

Universe ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 49
Author(s):  
Ying Jiang ◽  
Zhongxu Han ◽  
Qian Zhang ◽  
Weiqiang Yang ◽  
Yabo Wu ◽  
...  
Keyword(s):  
Dark Energy ◽  
Dark Energy Model ◽  
Cold Dark Matter ◽  
Coupling Parameter ◽  
Gravitational Interaction ◽  
Coupled Model ◽  
State Parameter ◽  
Energy Model ◽  
The State ◽  
Eos Parameter

In this paper, we have explored non-gravitational interaction dark energy model between dark energy and cold dark matter (CDM). The main purpose of this work is to explore the deviations from Λ C D M and to distinguish the evolution trajectory of the interaction dark energy model with different parameters. Six forms of interaction were focused on. We have analyzed the deceleration parameters of the coupled model and explored the theoretical models through s t a t e f i n d e r h i e r a r c h y and the O m diagnostic. We have considered that the Equation of State (EoS) parameter w and parameter ξ take different values on the interaction dark energy model respectively and keep another parameter unchanged. It was found that q ( z ) is the worst of the four diagnoses. O m , S 3 ( 1 ) and S 4 ( 1 ) are good tools to distinguish the interaction dark energy model from Λ C D M . S 3 ( 1 ) is a better diagnostic tool when the state parameter w changes and the coupling parameter ξ is fixed, while S 4 ( 1 ) works better when the coupling parameter ξ changes and the state parameter w is fixed.

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