- Research Article
- Open Access
Extensions of the results on powers of
-hyponormal and
-hyponormal operators
- Changsen Yang1Email author and
- Jiangtao Yuan1
https://doi.org/10.1155/JIA/2006/36919
© C. Yang and J. Yuan 2006
- Received: 22 November 2004
- Accepted: 10 May 2005
- Published: 9 March 2006
Abstract
Firstly, we will show the following extension of the results on powers of
-hyponormal and
-hyponormal operators: let
and
be positive integers, if
is
-hyponormal for
, then: (i) in case
,
and
hold, (ii) in case
,
and
hold. Secondly, we will show an estimation on powers of
-hyponormal operators for
which implies the best possibility of our results. Lastly, we will show a parallel estimation on powers of
-hyponormal operators as follows: let
, then the following hold for each positive integer
and
: (i) there exists a log-hyponormal operator
such that
, (ii) there exists a
-hyponormal operator
such that
.
Keywords
- Positive Integer
- Parallel Estimation
- Good Possibility
- Hyponormal Operator
Authors’ Affiliations
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