Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The road to solving the Gribov problem of the center vortex model in
  quantum chromo dynamics
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
6
The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess