Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Essential spectrum of a limit of self--adjoint operators   For a sequence of self--adjoint operators, which converges in the norm
resolvent sense, the formula is derived, which expresses the essential spectrum
of the limit through the essential spectrum of the elements of the sequence.

26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
18
The categories of this paper are: econ
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc