On a preorder relation for contractions
Functional Analysis
2016-05-26 v2
Abstract
An order relation for contractions on a Hilbert space can be introduced by stating that if and only is unitarily equivalent to the restriction of to an invariant subspace. We discuss the equivalence classes associated to this relation, and identify cases in which they coincide with classes of unitary equivalence. The results extend those for completely nonunitary partial isometries obtained by Garcia, Martin, and Ross.
Cite
@article{arxiv.1507.07128,
title = {On a preorder relation for contractions},
author = {Dan Timotin},
journal= {arXiv preprint arXiv:1507.07128},
year = {2016}
}
Comments
Revised version, correcting an incomplete proof. The paper will appear in Acta Scientiarum Mathematicarum (Szeged)