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Criteria for positively quadratically hyponormal weighted shifts
Author(s):
Ju Youn
Bae;
Il
Bong
Jung;
George
R.
Exner
Journal:
Proc. Amer. Math. Soc.
130
(2002),
3287-3294.
MSC (2000):
Primary 47B37, 47B20
Posted:
May 29, 2002
MathSciNet review:
1913008
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Abstract:
For bounded linear operators on Hilbert space, positive quadratic hyponormality is a property strictly between subnormality and hyponormality and which is of use in exploring the gap between these more familiar properties. Recently several related positively quadratically hyponormal weighted shifts have been constructed. In this note we establish general criteria for the positive quadratic hyponormality of weighted shifts which easily yield the results for these examples and other such weighted shifts.
References:
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Additional Information:
Ju Youn
Bae
Affiliation:
Department of Mathematics, College of Natural Sciences, Kyungpook National University, Taegu 702-701, Korea
Email:
baejuyoun@hanmir.com
Il
Bong
Jung
Affiliation:
Department of Mathematics, College of Natural Sciences, Kyungpook National University, Taegu 702-701, Korea
Email:
ibjung@kyungpook.ac.kr
George
R.
Exner
Affiliation:
Department of Mathematics, Bucknell University, Lewisburg, Pennsylvania 17837
Email:
exner@bucknell.edu
DOI:
10.1090/S0002-9939-02-06493-6
PII:
S 0002-9939(02)06493-6
Keywords:
Quadratically hyponormal operator,
positively quadratically hyponormal operator,
$k$-hyponormal operator
Received by editor(s):
September 28, 2000
Received by editor(s) in revised form:
June 11, 2001
Posted:
May 29, 2002
Additional Notes:
The first and second authors were supported by the Korea Research Foundation Grant (KRF-2000-015-DP0012).
Communicated by:
David R. Larson
Copyright of article:
Copyright
2002,
American Mathematical Society
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