Séminaire d'Analyse
Modulus of Continuity of Spectra of Pseudodifferential Operators and Applications to Gabor Analysis
Michael Speckbacher
( Vienne )Salle de conférences
le 20 mars 2025 à 14:00
In this talk, we consider one-parameter families of pseudodifferential
operators whose Weyl symbols are obtained by dilation and a smooth
deformation of a symbol in a weighted Sjöstrand class. We show that
their spectral edges are Lipschitz/Hölder continuous functions of the
dilation or deformation parameter. Suitably local estimates hold also
for the edges of every spectral gap.
These statements extend Bellissard’s seminal results on the Lipschitz
continuity of spectral edges for families of operators with periodic
symbols to a large class of symbols with only mild regularity
assumptions.
If time permits, we will also discuss how these results can be used to
study the behavior of the frame bounds of Gabor systems generated from
a dilated non-uniform set of time-frequency shifts.