One-dimensional perturbations of isometries (Q1073313)
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scientific article; zbMATH DE number 3944587
| Language | Label | Description | Also known as |
|---|---|---|---|
| English | One-dimensional perturbations of isometries |
scientific article; zbMATH DE number 3944587 |
Statements
One-dimensional perturbations of isometries (English)
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1986
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Let S be an isometry on a separable Hilbert space. The author gives a characterization of those operators F of rank one for which \(S+F\) is an isometry. Further he investigates for a pure isometry S when \(S+F\) becomes again a pure isometry. The problem is reduced to the investigation of a corresponding analytic function with positive real part.
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one-dimensional perturbation
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Hardy space
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isometry on a separable Hilbert space
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pure isometry
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analytic function with positive real part
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