2 papers
math.AP2026
Holomorphic Toroidal Pseudodifferential Operators on the Polydisk
Morten Nielsen
We give a necessary and sufficient triangular condition characterizing the toroidal pseudodifferential operators on that preserve the positive-frequency cone $\mathbb…
math.FA2026
On a Conjecture about Schauder-Basis Properties of the Daubechies Wavelet Packets
Morten Nielsen
Nielsen and Zhou (\emph{Mean size of wavelet packets}, ACHA 13 (2002), 22--34) conjectured that for every Daubechies filter of length at least four the associated wavelet packets f…