Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Accretion discs, low-mass protostars and planets: probing the impact of
  magnetic fields on stellar formation
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
33
The categories of this paper are: plasm-ph