Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Active region formation through the negative effective magnetic pressure
  instability
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
2
The categories of this paper are: math
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ