A note on joint hyponormality
Authors:
Scott McCullough and Vern Paulsen
Journal:
Proc. Amer. Math. Soc. 107 (1989), 187-195
MSC:
Primary 47B20
DOI:
https://doi.org/10.1090/S0002-9939-1989-0972236-8
MathSciNet review:
972236
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Abstract | References | Similar Articles | Additional Information
Abstract: We describe certain cones of polynomials in two variables naturally associated to the class(es) of operators for which the tuple
is jointly (weakly) hyponormal. As an application we give an example of an operator
such that the tuple
is jointly but not weakly hyponormal. Further, we show that there exists a polynomially hyponormal operator which is not subnormal if and only if there exists a weighted shift with the same property.
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Additional Information
DOI:
https://doi.org/10.1090/S0002-9939-1989-0972236-8
Keywords:
Jointly hyponormal
Article copyright:
© Copyright 1989
American Mathematical Society