English

A hyponormal weighted shift on a directed tree whose square has trivial domain

Functional Analysis 2011-04-28 v1

Abstract

It is proved that, up to isomorphism, there are only two directed trees that admit a hyponormal weighted shift with nonzero weights whose square has trivial domain. These are precisely those enumerable directed trees, one with root, the other without, whose every vertex has enumerable set of successors.

Keywords

Cite

@article{arxiv.1104.5195,
  title  = {A hyponormal weighted shift on a directed tree whose square has trivial domain},
  author = {Z. J. Jablonski and I. B. Jung and J. Stochel},
  journal= {arXiv preprint arXiv:1104.5195},
  year   = {2011}
}

Comments

8 pages

R2 v1 2026-06-21T17:59:25.391Z