On Some Normality-Like Properties and Bishop's Property (𝛽) for a Class of Operators on Hilbert Spaces

We prove some further properties of the operator 𝑇∈[𝑛QN] (𝑛-power quasinormal, defined in Sid Ahmed, 2011). In particular we show that the operator 𝑇∈[𝑛QN] satisfying the translation invariant property is normal and that the operator 𝑇∈[𝑛QN] is not supercyclic provided that it is not invertible. Als...

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Bibliographic Details
Main Author: Sid Ahmed Ould Ahmed Mahmoud
Format: Article
Language:English
Published: Hindawi Limited 2012-01-01
Series:International Journal of Mathematics and Mathematical Sciences
Online Access:http://dx.doi.org/10.1155/2012/975745
Description
Summary:We prove some further properties of the operator 𝑇∈[𝑛QN] (𝑛-power quasinormal, defined in Sid Ahmed, 2011). In particular we show that the operator 𝑇∈[𝑛QN] satisfying the translation invariant property is normal and that the operator 𝑇∈[𝑛QN] is not supercyclic provided that it is not invertible. Also, we study some cases in which an operator 𝑇∈[2QN] is subscalar of order 𝑚; that is, it is similar to the restriction of a scalar operator of order 𝑚 to an invariant subspace.
ISSN:0161-1712
1687-0425