Hostname: page-component-7479d7b7d-qlrfm Total loading time: 0 Render date: 2024-07-12T04:34:09.113Z Has data issue: false hasContentIssue false

HYPONORMAL OPERATORS, WEIGHTED SHIFTS AND WEAK FORMS OF SUPERCYCLICITY

Published online by Cambridge University Press:  02 February 2006

Frédéric Bayart
Affiliation:
Laboratoire Bordelais d’Analyse et de Géométrie, UMR 5467, Université Bordeaux 1, 351 Cours de la Libération, 33405 Talence Cedex, France (bayart@math.u-bordeaux1.fr; matheron@math.u-bordeaux1.fr)
Etienne Matheron
Affiliation:
Laboratoire Bordelais d’Analyse et de Géométrie, UMR 5467, Université Bordeaux 1, 351 Cours de la Libération, 33405 Talence Cedex, France (bayart@math.u-bordeaux1.fr; matheron@math.u-bordeaux1.fr)
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

An operator $T$ on a Banach space $X$ is said to be weakly supercyclic (respectively $N$-supercyclic) if there exists a one-dimensional (respectively $N$-dimensional) subspace of $X$ whose orbit under $T$ is weakly dense (respectively norm dense) in $X$. We show that a weakly supercyclic hyponormal operator is necessarily a multiple of a unitary operator, and we give an example of a weakly supercyclic unitary operator. On the other hand, we show that hyponormal operators are never $N$-supercyclic. Finally, we characterize $N$-supercyclic weighted shifts.

Type
Research Article
Copyright
Copyright © Edinburgh Mathematical Society 2006