Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Renormalization of the two-photon vacuum polarization and the self
  energy vacuum polarization for a tightly bound electron
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
17
The categories of this paper are: q-fin