Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Understanding Helical Magnetic Dynamo Spectra with a Nonlinear
  Four-Scale Theory
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
2
The categories of this paper are: math
1
The categories of this paper are: cs
20
The categories of this paper are: acc-phys