Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Viscous Flows and Conditions for Existence of Shocks in Relativistic
  Magnetic Hydrodynamics   We present a criterion for a shock wave existence in relativistic magnetic
hydrodynamics with an arbitrary (possibly non-convex) equation of state. The
criterion has the form of algebraic inequality that involves equation of state
of the fluid; it singles out the physical solutions and it can be easily
checked for any discontinuity satisfying concervation laws. The method of proof
uses introduction of small viscosity into the coupled set of equations of
motion of ideal relativistic fluid with infinite conductivity and Maxwell
equations.

23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci