English

Null-orbit reflexive operators

Functional Analysis 2011-01-13 v1 Operator Algebras

Abstract

We introduce and study the notion of null-orbit reflexivity, which is a slight perturbation of the notion of orbit-reflexivity. Positive results for orbit reflexivity and the recent notion of C\mathbb{C}-orbit reflexivity both extend to null-orbit reflexivity. Of the two known examples of operators that are not orbit-reflexive, one is null-orbit reflexive and the other is not. The class of null-orbit reflexive operators includes the classes of hyponormal, algebraic, compact, strictly block-upper (lower) triangular operators, and operators whose spectral radius is not 1. We also prove that every polynomially bounded operator on a Hilbert space is both orbit-reflexive and null-orbit reflexive.

Keywords

Cite

@article{arxiv.1101.2218,
  title  = {Null-orbit reflexive operators},
  author = {Don Hadwin and Ileana Ionascu and Hassan Yousefi},
  journal= {arXiv preprint arXiv:1101.2218},
  year   = {2011}
}
R2 v1 2026-06-21T17:10:39.757Z