Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Hard X-ray spectral variability of the brightest Seyfert AGN in the
  Swift/BAT sample
14
The categories of this paper are: math-ph
34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ