Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The unusual minimum of sunspot cycle 23 a consequence of Sun's
  meridional plasma flow variations
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
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg