Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Compressible Fluids: the discontinuity of the vorticity vector on a
  shock wave in thermodynamical variables   The discontinuity of the vorticity is written as a function of the vector T
grad s, (where T is the temperature and s the specific entropy). The expression
is obtained thanks to potential equations and independently of the mass
conservation and the equation of momentum balance.

36
The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat