Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A note on the contribution of multi-photon processes to radiative
  opacity
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
36
The categories of this paper are: cmp-lg
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph
35
The categories of this paper are: mtrl-th
13
The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg