Spherical maximal functions with fractal sets of dilations

by Prof. Joris Roos (University of Massachusetts Lowell)

Friday Jul 10, 2026, 2:15 PM → 3:15 PM Europe/Berlin

Endenicher Allee 60, Seminarraum 0.011 (Mathezentrum)

Abstract:

We will talk about spherical maximal functions in Euclidean space with arbitrary sets of dilations. There are interesting connections between various fractal dimensions of the dilation set and size estimates for the corresponding maximal operator. There is also a closely related problem on local smoothing estimates for the wave equation with fractal time sets. Based on joint works with Andreas Seeger, Tess Anderson, David Beltran, Marco Fraccaroli, Kevin Hughes and Alex Rutar.