Localized frames are finite unions of Riesz sequences
Feichtinger conjectured that every frame can be decomposed into a finite union of Riesz sequences. While the full conjecture remains open, the author proves it for frames satisfying a certain localization property. This abstract condition turns out to be satisfied for (irregular) Gabor systems generated by a function in a specified modulation space, and for the reproducing kernel frame associated to a shift-invariant space.
scientific article; zbMATH DE number 1896700