Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Bounds on the spectrum and reducing subspaces of a J-self-adjoint
  operator
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
36
The categories of this paper are: cmp-lg
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
23
The categories of this paper are: solv-int
21
The categories of this paper are: adap-org