Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Gauge-Independent Off-Shell Fermion Self-Energies at Two Loops: The
  Cases of QED and QCD
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph