activity
20242026
collaborators

6 papers

math.FA2026

Riesz sequences near the critical density

Marcin Bownik, Jordy Timo van Velthoven

We construct Riesz sequences whose Beurling density is arbitrary close to the critical density in the setting of reproducing kernel Hilbert spaces on metric measure spaces. In part…

math.FA2026

Uniform discretization of continuous frames

Marcin Bownik, Pu-Ting Yu

Let be an infinite-dimensional separable Hilbert space and let be a metric measure space satisfying the doubling and upper Alhfors regularity conditions at small scal…

math.FA2025

Frame redundancy and Beurling density

Marcin Bownik, Jordy Timo van Velthoven

We show that the frame measure function of a frame in certain reproducing kernel Hilbert spaces on metric measure spaces is given by the reciprocal of the Beurling density of its i…

math.CA2025

Meyer wavelets for rational dilations

Marcin Bownik

We show the existence of smooth band-limited multiresolution analysis (MRA) for any expansive dilation with real entries in any spatial dimension. We then prove the existence of or…

math.CA2024

On exponential frames near the critical density

Marcin Bownik, Jordy Timo van Velthoven

Given a relatively compact set of Lebesgue measure and , we show the existence of a set of uniform density $D…

math.CA2024

Selector form of Weaver's conjecture, Feichtinger's conjecture, and frame sparsification

Marcin Bownik

We show an extension of a probabilistic result of Marcus, Spielman, and Srivastava, which resolved the Kadison-Singer problem, for block diagonal positive semidefinite random matri…