Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: On Orders in Number Fields: Picard Groups, Ring Class Fields and
  Applications
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
7
The categories of this paper are: hep-th