Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Two-Stream Instability as a Mechanism for Toroidal Magnetic Field
  Generation in the Magnetosphere of Crab Pulsar
27
The categories of this paper are: comp-gas
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
35
The categories of this paper are: mtrl-th
26
The categories of this paper are: bayes-an
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs