Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Partial orders on partial isometries   This paper studies three natural pre-orders of increasing generality on the
set of all completely non-unitary partial isometries with equal defect indices.
We show that the problem of determining when one partial isometry is less than
another with respect to these pre-orders is equivalent to the existence of a
bounded (or isometric) multiplier between two natural reproducing kernel
Hilbert spaces of analytic functions. For large classes of partial isometries
these spaces can be realized as the well-known model subspaces and
deBranges-Rovnyak spaces. This characterization is applied to investigate
properties of these pre-orders and the equivalence classes they generate.

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The categories of this paper are: q-alg
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The categories of this paper are: acc-phys
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The categories of this paper are: nlin
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The categories of this paper are: dg-ga
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The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
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The categories of this paper are: supr-con
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The categories of this paper are: chem-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: solv-int
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The categories of this paper are: hep-ex
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The categories of this paper are: q-bio
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The categories of this paper are: hep-lat
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The categories of this paper are: nucl-ex
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The categories of this paper are: astro-ph