Dissipative Boltzmann-Robertson-Walker cosmologies

Journal Article · Wed May 15 04:00:00 EDT 1991 · Physical Review, D (Particles Fields); (USA)

DOI:https://doi.org/10.1103/PhysRevD.43.3249· OSTI ID:5796013

Hiscock, W A; Salmonson, J ^[1]

---

1. Department of Physics, Montana State University, Bozeman, Montana 59717 (US)

The equations governing a flat Robertson-Walker cosmological model containing a dissipative Boltzmann gas are integrated numerically. The bulk viscous stress is modeled using the Eckart and Israel-Stewart 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 Israel-Stewart 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 Israel-Stewart model the total pressure is asymptotically zero. The Eckart model also expands more rapidly than the Israel-Stewart models. These results suggest that bulk-viscous'' inflation may be an artifact of using a pathological fluid theory such as the Eckart theory.

• OSTI ID: 5796013
• Journal Information: Physical Review, D (Particles Fields); (USA), Journal Name: Physical Review, D (Particles Fields); (USA) Vol. 43:10; ISSN PRVDA; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

640106* -- Astrophysics & Cosmology-- Cosmology
657002 -- Theoretical & Mathematical Physics-- Classical & Quantum Mechanics
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BOLTZMANN STATISTICS
COSMIC GASES
COSMOLOGICAL MODELS
DISSIPATION FACTOR
FIELD THEORIES
FLUID FLOW
FLUIDS
GASES
GENERAL RELATIVITY THEORY
GRAVITATIONAL FIELDS
MATHEMATICAL MODELS
METRICS
PHYSICAL PROPERTIES
RELATIVITY THEORY
THERMODYNAMIC PROPERTIES
UNIVERSE
VISCOUS FLOW