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arXiv · 0903.4423

Curvature Condition for Noncontractions does not imply Similarity to the Backward Shift

Hyun-Kyoung Kwon·Sergei Treil
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Abstract

We give an example of an operator that satisfies the curvature condition as defined in [2], but is not similar to the backward shift S* on the Hardy class H^2. We conclude therefore that the contraction assumption in the similarity characterization given in [2] is a necessary requirement.

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Hyun-Kyoung Kwon, Sergei Treil. 2009-03-25. Curvature Condition for Noncontractions does not imply Similarity to the Backward Shift. https://arxiv.org/abs/0903.4423

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