Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A Dirac Sea and thermodynamic equilibrium for the quantized three-wave
  interaction
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
0
The categories of this paper are: hep-ph