✦ LIBER ✦
On extensions of some Flugede–Putnam type theorems involving (p, k)-quasihyponormal, spectral, and dominant operators
✍ Scribed by Kotaro Tanahashi; S. M. Patel; Atsushi Uchiyama
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 146 KB
- Volume
- 282
- Category
- Article
- ISSN
- 0025-584X
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✦ Synopsis
Abstract
A Hilbert space operator S is called (p, k)‐quasihyponormal if S *^k^ ((S *S)^p^ – (SS *)^p^ )S^k^ ≥ 0 for an integer k ≥ 1 and 0 < p ≤ 1. In the present note, we consider (p, k)‐quasihyponormal operator S ∈ B (H) such that SX = XT for some X ∈ B (K,H) and prove the Fuglede–Putnam type theorems when the adjoint of T ∈ B (K) is either (p, k)‐quasihyponormal or dominant or a spectral operator (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)