scholarly journals How effective is new variable modified Chaplygin gas to play the role of dark energy—a dynamical system analysis in RS II brane model

2013 ◽  
Vol 347 (2) ◽  
pp. 433-444 ◽  
Author(s):  
Prabir Rudra ◽  
Chayan Ranjit ◽  
Sujata Kundu
Keyword(s):  
Dynamical System ◽  
Dark Energy ◽  
System Analysis ◽  
Chaplygin Gas ◽  
Modified Chaplygin Gas ◽  
Brane Model ◽  
Variable Modified Chaplygin Gas

scholarly journals Dynamical system analysis of FLRW models with Modified Chaplygin gas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ali Osman Yılmaz ◽  
Ertan Güdekli
Keyword(s):  
Dynamical System ◽  
Equation Of State ◽  
Energy Density ◽  
System Analysis ◽  
Chaplygin Gas ◽  
Modified Chaplygin Gas ◽  
State Spaces ◽  
The Universe ◽  
Matter Energy ◽  
Far Future

AbstractWe investigate Friedmann–Lamaitre–Robertson–Walker (FLRW) models with modified Chaplygin gas and cosmological constant, using dynamical system methods. We assume $$p=(\gamma -1)\mu -\dfrac{A}{\mu ^\alpha }$$ p = ( γ - 1 ) μ - A μ α as equation of state where $$\mu$$ μ is the matter-energy density, p is the pressure, $$\alpha$$ α is a parameter which can take on values $$0<\alpha \le 1$$ 0 < α ≤ 1 as well as A and $$\gamma$$ γ are positive constants. We draw the state spaces and analyze the nature of the singularity at the beginning, as well as the fate of the universe in the far future. In particular, we address the question whether there is a solution which is stable for all the cases.

scholarly journals ROLE OF GENERALIZED COSMIC CHAPLYGIN GAS IN ACCELERATING UNIVERSE: A FIELD THEORETICAL PRESCRIPTION

2013 ◽  
Vol 28 (22) ◽  
pp. 1350102 ◽  
Author(s):  
PRABIR RUDRA
Keyword(s):  
Dark Energy ◽  
Chaplygin Gas ◽  
Point Of View ◽  
Accelerating Universe ◽  
Theoretical Point ◽  
Modified Chaplygin Gas ◽  
Statefinder Parameters ◽  
Generalized Cosmic Chaplygin Gas ◽  
The Given

In this paper, we investigate the role played by dark energy (DE) in the form of Generalized cosmic Chaplygin gas in an accelerating universe described by FRW cosmology. We have tried to describe the model from the theoretical point of view of a field, by introducing a scalar field ϕ and a self-interacting potential V(ϕ). The corresponding expressions for the field are obtained for the given model. Statefinder parameters have been used to characterize the dark energy model. Plots have been generated for characterizing different phases of universe diagrammatically and a comparative study is performed with the Modified Chaplygin gas model. As an outcome of the study, Generalized cosmic Chaplygin gas is identified as a much less constrained form of dark energy as compared to modified Chaplygin gas.

A VARIABLE MODIFIED CHAPLYGIN GAS MODEL WITH INTERACTION

2009 ◽  
Vol 18 (12) ◽  
pp. 1851-1862 ◽  
Author(s):  
LILI XING ◽  
YUANXING GUI ◽  
CHUNYAN WANG
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
State Parameter ◽  
Chaplygin Gas ◽  
Modified Chaplygin Gas ◽  
Phantom Divide ◽  
Energy Models ◽  
Big Rip ◽  
Variable Modified Chaplygin Gas ◽  
The Future

We consider in this paper a variable modified Chaplygin gas (VMCG) model for describing the unification of dark energy and dark matter, in which dark energy interacts with dark matter. Concretely, the evolution of the VMCG model with interaction is discussed and the statefinder diagnostic for the model is performed. By analysis, we find that the effective state parameter of dark energy can cross the phantom divide wΛ= -1 and our universe will not end up with a Big Rip in the future. Furthermore, we perform a statefinder analysis on this scenario and show the discrimination between this scenario and other dark energy models.

scholarly journals Role of a chameleon field in the presence of variable modified Chaplygin gas in Brans–Dicke theory

2012 ◽  
Vol 90 (2) ◽  
pp. 131-135 ◽  
Author(s):  
Shuvendu Chakraborty ◽  
Ujjal Debnath
Keyword(s):  
Scalar Field ◽  
Analytic Function ◽  
Chaplygin Gas ◽  
Conservation Equation ◽  
Modified Chaplygin Gas ◽  
Field Equations ◽  
Variable Modified Chaplygin Gas ◽  
The Universe ◽  
Friedmann Robertson Walker

In this work, we have considered the Friedmann–Robertson–Walker model of the universe for Brans–Dicke (BD) theory with a BD scalar field as a chameleon field. First we have transformed the field equations and conservation equation from Jordan’s frame to Einstein’s frame. We have shown that, in the presence of a variable modified Chaplygin gas (VMCG), the potential function V and another analytic function f always increase with respect to the BD–chameleon scalar field [Formula: see text] but decrease with time t for pure Chaplygin gas, modified Chaplygin gas, and VMCG models.

EVOLUTION OF VARIABLE MODIFIED CHAPLYGIN GAS MODEL

2009 ◽  
Vol 24 (09) ◽  
pp. 683-691 ◽  
Author(s):  
LILI XING ◽  
YUANXING GUI ◽  
LIXIN XU ◽  
JIANBO LU
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Early Time ◽  
State Parameter ◽  
Growth Index ◽  
Chaplygin Gas ◽  
The State ◽  
Modified Chaplygin Gas ◽  
Phantom Divide ◽  
Variable Modified Chaplygin Gas

We consider a variable modified Chaplygin gas (VMCG) model with unified dark energy and dark matter. Some cosmological quantities are studied, such as the state parameter of dark energy wde, the fractional energy densities Ωi(i respectively denotes baryons, dark matter, dark energy), the deceleration parameter q and the growth index f. By analysis, we find that the state parameter of dark energy can cross the phantom divide wΛ= -1, the behavior of VMCG is similar to radiation in the early time and will be quinessence model in the future. Therefore the universe will not end up with Big Rip.

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