Special Session 114: Recent Advances in Partial Differential Equations and Harmonic Analysis

Maximal operators of Zygmund type
Laurent Moonens
Universite Paris Saclay
France
Co-Author(s):    Galia Dafni, Emma D`Aniello, Giorgi Oniani
Abstract:
We will present recent results about maximal operators of Zygmund-type, i.e. of the form: $$ Mf(x):=\sup_{B\in B(x)} \frac{1}{|B|} \int_B |f|, $$ where, for each $x$ (in the $n$-th dimensional Euclidean space), $B(x)$ is a collection of parallelepipeds parallel to the coordinate axes (or, more generally, of convex sets) containing, or being ``close to'' $x$. Depending on the geometry of sets in the collections $B(x)$, one may wish to understand the optimal weak-type inequality $M$ enjoys. The talk will detail a few famous cases, and provide some new results on this front. If time permits, we shall also discuss some issues related to their behavior in BMO or ``moderated'' BMO spaces.