Wave speeds in the macroscopic extended model for ultrarelativistic gases

Journal Article · Fri Nov 15 00:00:00 EST 2013 · Journal of Mathematical Physics

DOI:https://doi.org/10.1063/1.4829365· OSTI ID:22251913

Borghero, F., E-mail: [e-mail] ^[1]; Demontis, F., E-mail: [e-mail] ^[2]; Pennisi, S., E-mail: [e-mail] ^[3]

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1. Dip. Matematica e Informatica, Università di Cagliari, Via Ospedale 72, 09124 Cagliari (Italy)
2. Dip. Matematica, Università di Cagliari, Viale Merello 92, 09123 Cagliari (Italy)
3. Dip. Matematica, Università di Cagliari, Via Ospedale 72, 09124 Cagliari (Italy)

Equations determining wave speeds for a model of ultrarelativistic gases are investigated. This model is already present in literature; it deals with an arbitrary number of moments and it was proposed in the context of exact macroscopic approaches in Extended Thermodynamics. We find these results: the whole system for the determination of the wave speeds can be divided into independent subsystems which are expressed by linear combinations, through scalar coefficients, of tensors all of the same order; some wave speeds, but not all of them, are expressed by square roots of rational numbers; finally, we prove that these wave speeds for the macroscopic model are the same of those furnished by the kinetic model.

• OSTI ID: 22251913
• Journal Information: Journal of Mathematical Physics, Vol. 54, Issue 11; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-2488
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EQUATIONS
GASES
RELATIVISTIC RANGE
SCALARS
TENSORS
THERMODYNAMICS
VELOCITY