View : 282 Download: 0

Square roots of hyponormal operators

- Title
- Square roots of hyponormal operators

- Ewha Authors
- 고응일

- Issue Date
- 1999

- Journal Title
- GLASGOW MATHEMATICAL JOURNAL

- ISSN
- 0017-0895

- Citation
- GLASGOW MATHEMATICAL JOURNAL vol. 41, pp. 463 - 470

- Publisher
- CAMBRIDGE UNIV PRESS

- Document Type
- Article

- Abstract
- An operator T is an element of L(H) is called a square root of a hyponormal operator if T-2 is hyponormal. In this paper, we prove the following results: Let S and T be square roots of hyponormal operators. (1) If sigma(T) boolean AND [-sigma(T)] = phi or {0}, then T is isoloid (i.e., every isolated point of sigma(T) is an eigenvalue of T). (2) If S and T commute, then ST is Weyl if and only if S and T are both Weyl. (3) If sigma(T) boolean AND [-sigma(T)] = phi, or {0}, then Weyl's theorem holds for T. (4) If sigma(T) boolean AND [-sigma(T)] = phi, then T is subscalar. As a corollary, we get that T has a nontrivial invariant subspace if sigma(T) has non-empty interior. (See [3].).

- Appears in Collections:
- 자연과학대학 > 수학전공 > Journal papers

- Files in This Item:

There are no files associated with this item.

- Export
- RIS (EndNote)
- XLS (Excel)
- XML

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.