Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Magnetic monopoles in pure $SU (2)$ Yang--Mills theory with a
  gauge-invariant mass
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
3
The categories of this paper are: physics