3 papers
math.FA2025
The Lifting Property for Frame Multipliers and Toeplitz Operators
Peter Balazs, Karlheinz Gröchenig
Frame multipliers are an abstract version of Toeplitz operators in frame theory and consist of a composition of a multiplication operator with the analysis and synthesis operators.…
math.FA2025
More Uncertainty Principles for Metaplectic Time-Frequency Representations
Karlheinz Gröchenig, Irina Shafkulovska
We develop a method for the transfer of an uncertainty principle for the short-time Fourier transform or a Fourier pair to an uncertainty principle for a sesquilinear or quadratic…
math.FA2024
Hölder-Continuity of Extreme Spectral Values of Pseudodifferential Operators, Gabor Frame Bounds, and Saturation
Karlheinz Gröchenig, José Luis Romero, Michael Speckbacher
We build on our recent results on the Lipschitz dependence of the extreme spectral values of one-parameter families of pseudodifferential operators with symbols in a weighted Sjös…