In the present context, where the field equations are given
by (79,
80
) this homogeneous algebraic system spreads out into three
equations, viz.
By (89) and (91
) this is a fully explicit system, if the thermal equation of
state
is known. The vanishing of its determinant determines the
characteristic speeds. Seccia & Strumia [44] have calculated these speeds - one transversal and two
longitudinal ones - for non-degenerate gases and obtained the
following results in the non-relativistic and ultra-relativistic
cases
All speeds are finite and smaller than c . Inspection shows that in the non-relativistic limit the order of magnitude of these speeds is that of the ordinary speed of sound, while in the ultra-relativistic case the speeds come close to c .
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Speeds of Propagation in Classical and Relativistic
Extended Thermodynamics
Ingo Müller http://www.livingreviews.org/lrr-1999-1 © Max-Planck-Gesellschaft. ISSN 1433-8351 Problems/Comments to livrev@aei-potsdam.mpg.de |