Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: An equivariant Atiyah-Patodi-Singer index theorem for proper actions I:
  the index formula
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
17
The categories of this paper are: q-fin
6
The categories of this paper are: astro-ph
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an
20
The categories of this paper are: acc-phys