2 papers
math.FA2026
Periodic Non-uniqueness Sets for Shift-invariant Spaces and Parity-Based Obstructions to the Frame Property for Gabor Systems
Alexander Ulanovskii, Ilya Zlotnikov
The goal of this note is twofold. First, we provide explicit examples of periodic (though not necessarily lattice) sets that give rise to Gabor systems failing to form frames. Our…
math.FA2026
Extreme and exposed points of shift-invariant spaces generated by Gaussian kernel and hyperbolic secant
Markus Valås Hagen, Alexander Ulanovskii, Denis Zelent +1
We characterize the extreme and exposed points of the unit ball (with respect to the -norm) in the shift-invariant space generated by the Gaussian function, as well as in the…