Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Square roots of some classical operators   In this paper we give complete descriptions of the set of square roots of
certain classical operators, often providing specific formulas. The classical
operators included in this discussion are the square of the unilateral shift,
the Volterra operator, certain compressed shifts, the unilateral shift plus its
adjoint, the Hilbert matrix, and the Ces\`{a}ro operator.

7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org