Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Application of the Lagrange-Souriau form method to the case of
  source-free electromagnetic field
0
The categories of this paper are: hep-ph
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
36
The categories of this paper are: cmp-lg
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
16
The categories of this paper are: stat
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin