Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Near-the-origin divergence of Dirac wave functions of hydrogen and
  operator product expansion
23
The categories of this paper are: solv-int
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat
20
The categories of this paper are: acc-phys
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an