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Moment sequences and backward extensions of subnormal weighted shifts

Part of: Integral transforms, operational calculus Special classes of linear operators

Published online by Cambridge University Press:  09 April 2009

Thomas Hoover ,
Il Bong Jung  and
Alan Lambert
Thomas Hoover
Affiliation:
Department of Mathematics, University of Hawaii, Honolulu, Hawaii 96822, USA e-mail: hoover@math.hawaii.edu
Il Bong Jung
Affiliation:
Department of Mathematics, College of Natural Sciences, Kyungpook National UniversityTaegu 702-701Korea e-mail: ibjung@kyungpook.ac.kr
Alan Lambert
Affiliation:
Department of Mathematics, University of North Carolina at Charlotte, UNCC Station Charlotte, NC 28223USA e-mail: allamber@email.uncc.edu
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Abstract

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In this note we examine the relationships between a subnormal shift, the measure its moment sequence generates, and those of a large family of weighted shifts associated with the original shift. We examine the effects on subnormality of adding a new weight or changing a weight. We also obtain formulas for evaluating point mass at the origin for the measure associated with the shift. In addition, we examine the relationship between the measure associated with a subnormal shift and those of a family of shifts substantially different from the original shift.

Keywords

weighted shiftssubnormal operatorsmoment sequences

MSC classification

Secondary: 47B20: Subnormal operators, hyponormal operators, etc. 47B37: Operators on special spaces (weighted shifts, operators on sequence spaces, etc.) 44A60: Moment problems
Type
Research Article
Information
Journal of the Australian Mathematical Society , Volume 73 , Issue 1 , August 2002 , pp. 27 - 36
Copyright
Copyright © Australian Mathematical Society 2002

References

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