QUANTUM PERFECT FLUID COSMOLOGICAL MODEL AND ITS CLASSICAL ANALOGUE

2002 ◽  
Vol 17 (20) ◽  
pp. 2749-2749
Author(s):  
A. B. BATISTA ◽  
J. C. FABRIS ◽  
S. V. B. GONCALVES ◽  
J. TOSSA
Keyword(s):  
Perfect Fluid ◽  
Fluid Model ◽  
Classical Model ◽  
Free Particle ◽  
Stiff Matter ◽  
Bouncing Universe ◽  
Quantization Of Gravity ◽  
Barotropic Equation ◽  
Classical Analogue ◽  
Perfect Fluid Models

The quantization of gravity coupled to a perfect fluid model leads to a Schrödinger-like equation, where the matter variable plays the role of time. The wave function can be determined, in the flat case, for an arbitrary barotropic equation of state p = α ρ; solutions can also be found for the radiative non-flat case. The wave packets are constructed, from which the expectation value for the scale factor is determined. The quantum scenarios reveal a bouncing Universe, free from singularity. Such quantum cosmological perfect fluid models admit a universal classical analogue, represented by the addition, to the ordinary classical model, of a repulsive stiff matter fluid1,2. The existence of this universal classical analogue may imply that this perfect fluid coupled to gravity model is not a real quantum system. The quantum cosmological perfect fluid model is, for a flat spatial section, formally equivalent to a free particle in ordinary quantum mechanics, for any value of α, while the radiative non-flat case is equivalent to the harmonic oscillator. The repulsive fluid needed to reproduce the quantum results is the same in both cases.

INFLATIONARY SCENARIO IN BRANS–DICKE THEORY FOR BIANCHI VI0 SPACE–TIME MODEL

2003 ◽  
Vol 12 (01) ◽  
pp. 129-143 ◽  
Author(s):  
SUBENOY CHAKRABORTY ◽  
ARABINDA GHOSH
Keyword(s):  
Equation Of State ◽  
Perfect Fluid ◽  
Analytical Solutions ◽  
Fluid Model ◽  
Space Time ◽  
Time Model ◽  
Exact Analytical Solutions ◽  
Exponential Expansion ◽  
Barotropic Equation ◽  
Space Time Model

We have investigated perfect fluid model in Brans–Dicke theory for Bianchi VI 0 space–time and have obtained exact analytical solutions considering barotropic equation of state. These solutions have been analyzed for different values of the parameters involved and some of them have shown a period of exponential expansion.

BRANS–DICKE THEORY IN BIANCHI III MODEL AND INFLATIONARY SCENARIO

2002 ◽  
Vol 11 (03) ◽  
pp. 391-404 ◽  
Author(s):  
NARAYAN CHANDRA CHAKRABORTY ◽  
SUBENOY CHAKRABORTY
Keyword(s):  
Equation Of State ◽  
Perfect Fluid ◽  
Analytical Solutions ◽  
Fluid Model ◽  
Space Time ◽  
Exact Analytical Solutions ◽  
Inflationary Scenario ◽  
Bianchi Iii ◽  
Barotropic Equation

Brans–Dicke theory with perfect fluid model has been considered in Bianchi III space–time and exact analytical solutions are presented with barotropic equation of state. These solutions have been analyzed and some of them have shown the properties of inflationary scenario.

scholarly journals Quantum cosmological perfect fluid model and its classical analogue

2002 ◽  
Vol 65 (6) ◽  
Author(s):  
A. B. Batista ◽  
J. C. Fabris ◽  
S. V. B. Gonçalves ◽  
J. Tossa
Keyword(s):  
Perfect Fluid ◽  
Fluid Model ◽  
Classical Analogue

Perfect fluid model with g = 2

2021 ◽  
Vol 34 (2) ◽  
pp. 224-226
Author(s):  
John French
Keyword(s):  
Simple Model ◽  
Angular Velocity ◽  
Special Relativity ◽  
Perfect Fluid ◽  
Fluid Model ◽  
Classical Model ◽  
Model Based ◽  
A Value

A perfect fluid model with a shell of charge is presented which yields g = 2 for low angular velocity. This model is not intended to represent a classical model of the electron but to show that a simple model based on equations consistent with special relativity can yield a value of g = 2.

Bianchi type-V perfect fluid models

1986 ◽  
Vol 18 (1) ◽  
pp. 79-91 ◽  
Author(s):  
B. K. Nayak ◽  
G. B. Bhuyan
Keyword(s):  
Perfect Fluid ◽  
Bianchi Type ◽  
Fluid Models ◽  
Perfect Fluid Models ◽  
Type V ◽  
Bianchi Type V

scholarly journals A perfect fluid model for compact stars

2019 ◽  
Vol 97 (9) ◽  
pp. 988-993 ◽  
Author(s):  
Gabino Estevez-Delgado ◽  
Joaquin Estevez-Delgado ◽  
Nadiezhda Montelongo García ◽  
Modesto Pineda Duran
Keyword(s):  
Perfect Fluid ◽  
Fluid Model ◽  
Compact Stars

scholarly journals Bénard Problem for Slightly Compressible Fluids: Existence and Nonlinear Stability in 3D

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Arianna Passerini
Keyword(s):  
Pressure Field ◽  
Fluid Model ◽  
Classical Model ◽  
Compressible Fluids ◽  
Heat Conducting ◽  
Regular Solutions ◽  
New Approach ◽  
Slightly Compressible ◽  
Bénard Problem ◽  
Benard Problem

This paper shows the existence, uniqueness, and asymptotic behavior in time of regular solutions (a la Ladyzhenskaya) to the Bénard problem for a heat-conducting fluid model generalizing the classical Oberbeck–Boussinesq one. The novelty of this model, introduced by Corli and Passerini, 2019, and Passerini and Ruggeri, 2014, consists in allowing the density of the fluid to also depend on the pressure field, which, as shown by Passerini and Ruggeri, 2014, is a necessary request from a thermodynamic viewpoint when dealing with convective problems. This property adds to the problem a rather interesting mathematical challenge that is not encountered in the classical model, thus requiring a new approach for its resolution.

scholarly journals QUANTUM PERFECT-FLUID KALUZA–KLEIN COSMOLOGY

2006 ◽  
Vol 21 (22) ◽  
pp. 4463-4477
Author(s):  
WUNG-HONG HUANG ◽  
I-CHIN WANG
Keyword(s):  
Wave Packet ◽  
Perfect Fluid ◽  
Final Stage ◽  
Quantum Effect ◽  
Scale Functions ◽  
First Case ◽  
Bohmian Trajectories ◽  
Klein Theory ◽  
Barotropic Equation ◽  
Kaluza Klein

The perfect-fluid cosmology in the (1+d+D)-dimensional Kaluza–Klein space–times for an arbitrary barotropic equation of state p = (γ-1)ρ is quantized by using the Schutz's variational formalism. We make efforts in the mathematics to solve the problems in two cases. In the first case of the stiff fluid γ = 2 we exactly solve the Wheeler–DeWitt equation when the d space is flat. After the superposition of the solutions the wave-packet function is obtained exactly. We analyze the Bohmian trajectories of the final-stage wave-packet functions and show that the scale functions of the flat d spaces and the compact D spaces will eventually evolve into the nonzero finite values. In the second case of γ≈2, we use the approximated wave function in the Wheeler–DeWitt equation to find the analytic forms of the final-stage wave-packet functions. After analyzing the Bohmian trajectories we show that the flat d spaces will be expanding forever while the scale function of the contracting D spaces would not become zero within finite time. Our investigations indicate that the quantum effect in the quantum perfect-fluid cosmology could prevent the extra compact D spaces in the Kaluza–Klein theory from collapsing into a singularity or that the "crack-of-doom" singularity of the extra compact dimensions is made to occur at t = ∞.

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