3 papers
math.FA2026
Triebel-Lizorkin spaces and expansive matrices
Marcin Bownik, Jordy Timo van Velthoven
We survey recent classification theorems for expansive matrices that generate the same anisotropic homogeneous Triebel-Lizorkin function space or sequence space. The function space…
math.CA2025
Are MSF wavelets minimally supported?
Marcin Bownik, Ziemowit Rzeszotnik, Darrin Speegle
Larson's problem asks ``Must the support of the Fourier transform of a wavelet contain a wavelet set?". We give an affirmative answer to a non-measurable variant of this question b…
math.CA2025
Extrapolation and Factorization of matrix weights
Marcin Bownik, David Cruz-Uribe
In this paper we prove the Jones factorization theorem and the Rubio de Francia extrapolation theorem for matrix weights. These results answer longstanding open ques…