Dissipative BoltzmannRobertsonWalker cosmologies
Abstract
The equations governing a flat RobertsonWalker cosmological model containing a dissipative Boltzmann gas are integrated numerically. The bulk viscous stress is modeled using the Eckart and IsraelStewart theories of dissipative relativistic fluids; the resulting cosmologies are compared and contrasted. The Eckart models are shown to always differ in a significant quantitative way from the IsraelStewart models. It thus appears inappropriate to use the pathological (nonhyperbolic) Eckart theory for cosmological applications. For large bulk viscosities, both cosmological models approach asymptotic nonequilibrium states; in the Eckart model the total pressure is negative, while in the IsraelStewart model the total pressure is asymptotically zero. The Eckart model also expands more rapidly than the IsraelStewart models. These results suggest that bulkviscous'' inflation may be an artifact of using a pathological fluid theory such as the Eckart theory.
 Authors:
 (Department of Physics, Montana State University, Bozeman, Montana 59717 (US))
 Publication Date:
 OSTI Identifier:
 5796013
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physical Review, D (Particles Fields); (USA); Journal Volume: 43:10
 Country of Publication:
 United States
 Language:
 English
 Subject:
 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COSMOLOGICAL MODELS; UNIVERSE; COSMIC GASES; BOLTZMANN STATISTICS; DISSIPATION FACTOR; GRAVITATIONAL FIELDS; METRICS; RELATIVITY THEORY; THERMODYNAMIC PROPERTIES; VISCOUS FLOW; FIELD THEORIES; FLUID FLOW; FLUIDS; GASES; GENERAL RELATIVITY THEORY; MATHEMATICAL MODELS; PHYSICAL PROPERTIES; 640106*  Astrophysics & Cosmology Cosmology; 657002  Theoretical & Mathematical Physics Classical & Quantum Mechanics
Citation Formats
Hiscock, W.A., and Salmonson, J. Dissipative BoltzmannRobertsonWalker cosmologies. United States: N. p., 1991.
Web. doi:10.1103/PhysRevD.43.3249.
Hiscock, W.A., & Salmonson, J. Dissipative BoltzmannRobertsonWalker cosmologies. United States. doi:10.1103/PhysRevD.43.3249.
Hiscock, W.A., and Salmonson, J. 1991.
"Dissipative BoltzmannRobertsonWalker cosmologies". United States.
doi:10.1103/PhysRevD.43.3249.
@article{osti_5796013,
title = {Dissipative BoltzmannRobertsonWalker cosmologies},
author = {Hiscock, W.A. and Salmonson, J.},
abstractNote = {The equations governing a flat RobertsonWalker cosmological model containing a dissipative Boltzmann gas are integrated numerically. The bulk viscous stress is modeled using the Eckart and IsraelStewart theories of dissipative relativistic fluids; the resulting cosmologies are compared and contrasted. The Eckart models are shown to always differ in a significant quantitative way from the IsraelStewart models. It thus appears inappropriate to use the pathological (nonhyperbolic) Eckart theory for cosmological applications. For large bulk viscosities, both cosmological models approach asymptotic nonequilibrium states; in the Eckart model the total pressure is negative, while in the IsraelStewart model the total pressure is asymptotically zero. The Eckart model also expands more rapidly than the IsraelStewart models. These results suggest that bulkviscous'' inflation may be an artifact of using a pathological fluid theory such as the Eckart theory.},
doi = {10.1103/PhysRevD.43.3249},
journal = {Physical Review, D (Particles Fields); (USA)},
number = ,
volume = 43:10,
place = {United States},
year = 1991,
month = 5
}

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