Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Proper actions, fixed-point algebras and naturality in nonabelian
  duality
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph