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$k$-hyponormality of powers of weighted shifts via Schur products

Author(s): Raúl Curto; Sang Soo Park
Journal: Proc. Amer. Math. Soc. 131 (2003), 2761-2769.
MSC (1991): Primary 47B37, 47B20; Secondary 47-04, 47A13
Posted: November 13, 2002
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Abstract: We characterize $k$-hyponormality and quadratic hyponormality of powers of weighted shifts using Schur product techniques.

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Additional Information:

Raúl Curto
Affiliation: Department of Mathematics, The University of Iowa, Iowa City, Iowa 52242
Email: curto@math.uiowa.edu

Sang Soo Park
Affiliation: Department of Mathematics, Kyungpook National University, Deagu, Korea
Email: pss4855@hanmail.net

DOI: 10.1090/S0002-9939-02-06805-3
PII: S 0002-9939(02)06805-3
Keywords: $k$-hyponormality, powers of weighted shifts, Schur products
Received by editor(s): October 5, 2001
Received by editor(s) in revised form: March 27, 2002
Posted: November 13, 2002
Additional Notes: The research of the first author was partially supported by NSF grant DMS-9800931
The research of the second author was partially supported by KOSEF research project no. R01-2000-00003
Communicated by: Joseph A. Ball
Copyright of article: Copyright 2002, American Mathematical Society

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