scholarly journals Dynamics of Mixed Dark Energy Domination in Teleparallel Gravity and Phase-Space Analysis

2015 ◽  
Vol 2015 ◽  
pp. 1-20 ◽  
Author(s):  
Emre Dil ◽  
Erdinç Kolay
Keyword(s):  
Dark Energy ◽  
Phase Space ◽  
Scalar Fields ◽  
Teleparallel Gravity ◽  
Late Time ◽  
Baryonic Matter ◽  
Acceleration Phase ◽  
Phase Space Analysis ◽  
Space Analysis ◽  
Phantom Scalar

We consider a novel dark energy model to investigate whether it will provide an expanding universe phase. Here we propose a mixed dark energy domination which is constituted by tachyon, quintessence, and phantom scalar fields nonminimally coupled to gravity, in the absence of background dark matter and baryonic matter, in the framework of teleparallel gravity. We perform the phase-space analysis of the model by numerical methods and find the late-time accelerated attractor solutions implying the acceleration phase of universe.

Phase space analysis of the Umami Chaplygin model

2021 ◽  
pp. 2150052
Author(s):  
Qihong Huang ◽  
Ruanjing Zhang ◽  
Jun Chen ◽  
He Huang ◽  
Feiquan Tu
Keyword(s):  
Phase Space ◽  
Cosmic Acceleration ◽  
Accelerated Expansion ◽  
Late Time ◽  
Phase Space Analysis ◽  
Space Analysis ◽  
History Of ◽  
Evolutionary Trajectories ◽  
The Universe ◽  
Universe Evolution

In this paper, we analyze the universe evolution and phase space behavior of the Umami Chaplygin model, where the Umami Chaplygin fluid replaces both a dark energy and a dark and baryonic matter. We find the Umami Chaplygin model can be stable against perturbations under some conditions and can be used to explain the late-time cosmic acceleration. The results of phase space analysis show that there exists a late-time accelerated expansion attractor with [Formula: see text], which indicates the Umami Chaplygin fluid can behave as a cosmological constant. Moreover, the Umami Chaplygin model can describe the expansion history of the universe. The evolutionary trajectories of the statefinder diagnostic pairs and the finite time future singularities are also discussed.

A varying polytropic gas universe and phase space analysis

2016 ◽  
Vol 31 (16) ◽  
pp. 1650097 ◽  
Author(s):  
M. Khurshudyan
Keyword(s):  
Phase Space ◽  
Large Scale ◽  
Accelerated Expansion ◽  
Late Time ◽  
Mathematical Tool ◽  
Phase Space Analysis ◽  
Space Analysis ◽  
Polytropic Gas ◽  
Dark Fluid ◽  
Large Scale Universe

In this paper, we will consider a phenomenological model of a dark fluid that is able to explain an accelerated expansion of our low redshift universe and the phase transition to this accelerated expanding universe. Recent developments in modern cosmology towards understanding of the accelerated expansion of the large scale universe involve various scenarios and approaches. Among these approaches, one of well-known and accepted practice is modeling of the content of our universe via dark fluid. There are various models of dark energy fluid actively studied in recent literature and polytropic gas is among them. In this work, we will consider a varying polytropic gas which is a phenomenological modification of polytropic gas. Our model of varying polytropic dark fluid has been constructed to analogue to a varying Chaplygin gas actively discussed in the literature. We will consider interacting models, where dark matter is a pressureless fluid, to have a comprehensive picture. Phase space analysis is an elegant mathematical tool to earn general understanding of large scale universe and easily see an existence of a solution to cosmological coincidence problem. Imposing some constraints on parameters of the models, we found late time attractors for each case analytically. Cosmological consequences for the obtained late time attractors are discussed.

scholarly journals A NOTE ON THE COSMOLOGICAL DYNAMICS IN FINITE-RANGE GRAVITY

2003 ◽  
Vol 12 (04) ◽  
pp. 689-696 ◽  
Author(s):  
M. SAMI
Keyword(s):  
Phase Space ◽  
Gravity Theory ◽  
Accelerated Expansion ◽  
Late Time ◽  
Finite Range ◽  
Phase Space Analysis ◽  
Space Analysis ◽  
Late Time Acceleration ◽  
Isotropic Cosmology ◽  
The Universe

In this note we consider the homogeneous and isotropic cosmology in the finite-range gravity theory recently proposed by Babak and Grishchuk. In this scenario the universe undergoes late time accelerated expansion if both the massive gravitons present in the model are tachyons. We carry out the phase space analysis of the system and show that the late-time acceleration is an attractor of the model.

Phase-space analysis on interactions in dark energy models

2012 ◽  
Vol 72 (6) ◽  
Author(s):  
Yi Zhang ◽  
Hui Li ◽  
Yungui Gong ◽  
Zong-Hong Zhu
Keyword(s):  
Dark Energy ◽  
Phase Space ◽  
Phase Space Analysis ◽  
Space Analysis ◽  
Energy Models

scholarly journals Dynamics of Interacting Tachyonic Teleparallel Dark Energy

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Ali Banijamali
Keyword(s):  
Dark Energy ◽  
Phase Space ◽  
Scalar Field ◽  
Teleparallel Gravity ◽  
Late Time ◽  
Coincidence Problem

We consider a tachyon scalar field which is nonminimally coupled to gravity in the framework of teleparallel gravity. We analyze the phase-space of the model, known as tachyonic teleparallel dark energy, in the presence of an interaction between dark energy and background matter. We find that although there exist some late-time accelerated attractor solutions, there is no scaling attractor. So, unfortunately interacting tachyonic teleparallel dark energy cannot alleviate the coincidence problem.

scholarly journals Phase-space analysis of teleparallel dark energy

2012 ◽  
Vol 2012 (07) ◽  
pp. 005-005 ◽  
Author(s):  
Chen Xu ◽  
Emmanuel N Saridakis ◽  
Genly Leon
Keyword(s):  
Dark Energy ◽  
Phase Space ◽  
Phase Space Analysis ◽  
Space Analysis

scholarly journals Couplingq-Deformed Dark Energy to Dark Matter

2016 ◽  
Vol 2016 ◽  
pp. 1-20 ◽  
Author(s):  
Emre Dil
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Phase Space ◽  
Scalar Field ◽  
Dark Energy Model ◽  
Cosmological Parameters ◽  
Energy Model ◽  
Late Time ◽  
Acceleration Phase ◽  
Energy Models

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.

scholarly journals Phase space analysis of a FRW cosmology in the Maxwell–Cattaneo approach

2018 ◽  
Vol 27 (16) ◽  
pp. 1950001 ◽  
Author(s):  
Yoelsy Leyva
Keyword(s):  
Dark Matter ◽  
Phase Space ◽  
Bulk Viscosity ◽  
Early Time ◽  
Late Time ◽  
Stiff Matter ◽  
Phase Space Analysis ◽  
Space Analysis ◽  
Perfect Fluids ◽  
Frw Model

In this work, we present a phase space analysis of a spatially flat Friedmann–Robertson–Walker (FRW) model in which the dark matter fluid is modeled as an imperfect fluid having bulk viscosity. The bulk viscosity is governed by the Maxwell–Cattaneo approach. The rest of the components of the model — radiation and dark energy — are treated as perfect fluids. Imposing a complete cosmological dynamics and taking into account a recent constraint on the dark matter equation-of-state (EOS), we obtain bound on the bulk viscosity. We show that is possible to describe transitions from radiation-dominated to matter-dominated period, which then evolves to a stable accelerated solution of late time. At early time, before the radiation-dominated epoch, the model suggests the presence of an unstable stiff matter solution which is not possible to associate with a viable configuration in the early universe.

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