scholarly journals Bulk Viscous Cosmological Model in Brans-Dicke Theory with New Form of Time Varying Deceleration Parameter

2017 ◽  
Vol 2017 ◽  
pp. 1-24
Author(s):  
G. P. Singh ◽  
Binaya K. Bishi
Keyword(s):  
Equation Of State ◽  
Cosmological Model ◽  
Bulk Viscosity ◽  
Deceleration Parameter ◽  
Chaplygin Gas ◽  
Time Varying ◽  
Modified Chaplygin Gas ◽  
Bulk Viscous ◽  
New Form ◽  
Frw Cosmological Model

We have presented FRW cosmological model in the framework of Brans-Dicke theory. This paper deals with a new proposed form of deceleration parameter and cosmological constant Λ. The effect of bulk viscosity is also studied in the presence of modified Chaplygin gas equation of state (p=Aρ-B/ρn). Furthermore, we have discussed the physical behaviours of the models.

scholarly journals FRW Cosmological Model with Modified Chaplygin Gas and Dynamical System

2012 ◽  
Vol 51 (9) ◽  
pp. 2754-2758 ◽  
Author(s):  
Nairwita Mazumder ◽  
Ritabrata Biswas ◽  
Subenoy Chakraborty
Keyword(s):  
Dynamical System ◽  
Cosmological Model ◽  
Chaplygin Gas ◽  
Modified Chaplygin Gas ◽  
Frw Cosmological Model

Interacting modified Chaplygin gas cosmology with varying viscosity

2014 ◽  
Vol 92 (11) ◽  
pp. 1470-1473
Author(s):  
K. Karimiyan ◽  
J. Naji
Keyword(s):  
Energy Density ◽  
Bulk Viscosity ◽  
Deceleration Parameter ◽  
Cosmological Parameters ◽  
Chaplygin Gas ◽  
Baryonic Matter ◽  
Modified Chaplygin Gas ◽  
Hubble Expansion ◽  
Interaction Interaction ◽  
Varying Viscosity

We study interacting modified Chaplygin gas, which has shear and bulk viscosities. We assume bulk viscosity is a function of density, and also consider sign-changeable interaction. Interaction is assumed between modified Chaplygin gas and baryonic matter. Then, the effects of viscosities on the cosmological parameters, such as energy, density, Hubble expansion parameter, scale factor, and deceleration parameter, are investigated. We can consider this model as a toy model of our universe.

scholarly journals Modified Chaplygin gas cosmology with bulk viscosity

2014 ◽  
Vol 23 (10) ◽  
pp. 1450082 ◽  
Author(s):  
H. B. Benaoum
Keyword(s):  
Numerical Methods ◽  
Cosmological Model ◽  
Bulk Viscosity ◽  
Chaplygin Gas ◽  
Modified Chaplygin Gas ◽  
Statefinder Parameters ◽  
Viscosity Parameter ◽  
Model Solutions

In this paper, we investigate the viscous modified Chaplygin gas cosmological model. Solutions for different values of the viscosity parameter are obtained using both analytical and numerical methods. We have calculated the deceleration and defined newly statefinder {r, s} pair in D dimensions. It is shown that when D = 4, the usual statefinder parameters are recovered. Furthermore, we apply the statefinder diagnostic to the MCG model with and without viscosity in D dimensions and explore these parameters graphically.

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 An Attempt for an Emergent Scenario with Modified Chaplygin Gas

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Sourav Dutta ◽  
Sudeshna Mukerji ◽  
Subenoy Chakraborty
Keyword(s):  
Equation Of State ◽  
Chaplygin Gas ◽  
Space Time ◽  
Modified Chaplygin Gas ◽  
Emergent Universe ◽  
Emergent Scenario ◽  
The Universe

The present work is an attempt for emergent universe scenario with modified Chaplygin gas. The universe is chosen as spatially flat FRW space-time with modified Chaplygin gas as the only cosmic substratum. It is found that emergent scenario is possible for some specific (unrealistic) choice of the parameters in the equation of state for modified Chaplygin gas.

VISCOUS GENERALIZED CHAPLYGIN GAS

2006 ◽  
Vol 15 (08) ◽  
pp. 1151-1161 ◽  
Author(s):  
XIANG-HUA ZHAI ◽  
YOU-DONG XU ◽  
XIN-ZHOU LI
Keyword(s):  
Equation Of State ◽  
Bulk Viscosity ◽  
Critical Energy ◽  
State Equation ◽  
Chaplygin Gas ◽  
Point Of View ◽  
Dynamical Analysis ◽  
Density Parameter ◽  
Generalized Chaplygin Gas ◽  
Barotropic Fluid

Viscous generalized Chaplygin gas (GCG) cosmology is discussed, assuming that there is bulk viscosity in the linear barotropic fluid and GCG. wγ = γ - 1 and wg represent the state equation parameters for barotropic fluid and GCG, respectively, in which γ = 1 or [Formula: see text] corresponds to ordinary matter or radiation. The dynamical analysis indicates that the phase [Formula: see text] is a dynamical attractor and the equation of state of GCG approaches it from either wg > -1 or wg < -1 depending on the choice of its initial cosmic density parameter and the ratio of pressure to critical energy density, where τg and τγ are viscosity parameters. Therefore, the equation of state wg will cross the boundary wg = -1 if we choose initial value wg < -1. Furthermore, we show that bulk viscosity coefficients should satisfy inequalities from the point of view of dynamics.

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