Abstract
In this paper, we consider the special case of the question raised by Halmos (see below). In particular, we show that if T k is p-hyponormal, then T is a subscalar operator of order 4k. As a corollary, we obtain that if T k is p-hyponormal and σ(T) has nonempty interior in the plane, then T has a nontrivial invariant subspace.
Original language | English |
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Pages (from-to) | 173-187 |
Number of pages | 15 |
Journal | Integral Equations and Operator Theory |
Volume | 59 |
Issue number | 2 |
DOIs | |
State | Published - Oct 2007 |
Bibliographical note
Funding Information:The work was supported by the Korea Research Foundation Grant funded by the Korean Government(MOEHRD, Basic Research Promotion Fund) (KRF-2006-312-C00461).
Keywords
- Invariant subspace
- P-hyponormality
- Subscalarity
- The property (β)