A Beurling-helson Type Theorem for Modulation Spaces

Abstract

We prove a Beurling-Helson type theorem on modulation spaces. More precisely, we show that the only C changes of variables that leave invariant the modulation spaces M(R) are affine functions on R. A special case of our result involving the Sjöstrand algebra was considered earlier by A. Boulkhemair. 

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Cite this paper

@inproceedings{Okoudjou2007ABT, title={A Beurling-helson Type Theorem for Modulation Spaces}, author={Kasso A. Okoudjou}, year={2007} }