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Article
Nonminimal Cyclic Invariant Subspaces of Hyperbolic Composition Operators
Contemporary Mathematics
  • Valentin Matache, University of Nebraska at Omaha
Author ORCID Identifier

Valentin Matache

Document Type
Article
Publication Date
1-1-2017
Disciplines
Abstract

Operators on function spaces acting by composition to the right with a fixed self-map ϕ are called composition operators. We denote them Cϕ. Given ϕ, a hyperbolic disc automorphism, the composition operator Cϕ on the Hilbert Hardy space H2 is considered. The bilateral cyclic invariant subspaces Kf, f ∈ H2, of Cϕ are studied, given their connection with the invariant subspace problem, which is still open for Hilbert space operators. We prove that nonconstant inner functions u induce non–minimal cyclic subspaces Ku if they have unimodular, orbital, cluster points. Other results about Ku when u is inner are obtained. If f ∈ H2 \ {0} has a bilateral orbit under Cϕ, with Cesàro means satisfying certain boundedness conditions, we prove Kf is non–minimal invariant under Cϕ. Other results proving the non–minimality of invariant subspaces of Cϕ of type Kf when f is not an inner function are obtained as well.

Comments

First published in Contemporary Mathematics 699 (2017), published by the American Mathematical Society. © 2016 American Mathematical Society.

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Citation Information
Valentin Matache. "Nonminimal Cyclic Invariant Subspaces of Hyperbolic Composition Operators" Contemporary Mathematics Vol. 699 (2017) p. 247 - 262
Available at: http://works.bepress.com/valentin-matache/28/