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COMPOSITION OPERATORS ON FINITE RANK MODEL SUBSPACES

Published online by Cambridge University Press:  02 August 2012

JAVAD MASHREGHI
Affiliation:
Département de mathématiques et de statistique, Université Laval, Québec G1K 7P4, Canada e-mail: javad.mashreghi@mat.ulaval.ca
MAHMOOD SHABANKHAH
Affiliation:
Department of Mathematics and Statistics, McGill University, Montreal, Québec H3A 2K6, Canada e-mail: mshaban@math.mcgill.ca
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Abstract

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We give a complete description of bounded composition operators on model subspaces KB, where B is a finite Blaschke product. In particular, if B has at least one finite pole, we show that the collection of all bounded composition operators on KB has a group structure. Moreover, if B has at least two distinct finite poles, this group is finite and cyclic.

Type
Research Article
Copyright
Copyright © Glasgow Mathematical Journal Trust 2012

References

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