Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Maps preserving the spectrum of certain products of operators   Let H be a complex Hilbert space, B(H) and S(H) be the spaces of all bounded
operators and all self-adjoint operators on H, respectively. We give the
concrete forms of the maps on B(H) and also S(H) which preserve the spectrum of
certain products of operators.

5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
35
The categories of this paper are: mtrl-th
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph