Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Cosmological Alfv\'en waves in the recent CMB data, and the
  observational bound on the primordial vector perturbation
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org