Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Recombination process for hydrogen atom in presence of blackbody
  radiation
5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an