© 2002 by London Mathematical Society
© The London Mathematical Society
Uniform Eigenvalue Estimates for Time-Frequency Localization Operators
Dipartimento di Metodi e Modelli Matematici, Piazzale J. F. Kennedy Pad. D, 16129 Genova, Italy
Department of Mathematics, University of Vienna Strudlhofgasse 4, A-1090 Vienna, Austria
Department of Mathematics and Computer Science, Drexel University 3141 Chestnut Street, Philadelphia, PA 19104-2875, USA
Received 31 October 2000. Revision received 16 July 2001.
Time-variant filters based on Calderón and Gabor reproducing formulas are important tools in time-frequency analysis. The paper studies the behavior of the eigenvalues of these filters. Optimal two-sided estimates of the number of eigenvalues contained in the interval (
1,
2), where 0<
1<
2<1, are obtained. The estimates cover large classes of localization domains and generating functions.