Characterization of the continuity properties of maximal operators associated to critical radius functions via Dini type conditions
Fabio Berra, Marilina Carena, Gladis Pradolini
TL;DR
The paper characterizes the continuity properties of Luxemburg-type maximal operators associated to a critical radius function within Orlicz and Zygmund spaces, via a Dini-type condition. It develops equivalences that connect this Dini-type control to boundedness and modular-type inequalities, including Fefferman-Stein-type results, for M_η^{ρ,σ}. It also proves weak-type modular bounds and shows boundedness of the associated Hardy-Littlewood maximal operator on L^{Φ}(w) spaces under A_p^{ρ} weights. Overall, it extends prior Luxemburg maximal operator theory to settings with critical radii, providing a robust framework for weighted continuity across generalized function spaces.
Abstract
We give a characterization of the continuity properties of a Luxemburg maximal type operator associated to a critical radius function $ρ$ between Orlicz spaces. This goal is achieved by means of a Dini type condition that includes certain Young functions related to the maximal operator and the spaces involved. Our results provide not only weak Fefferman-Stein type inequalities but also a weak weighted estimate of modular type for the considered operators, which is interesting in its own right. On the other hand, we prove the boundedness of the Hardy-Littlewood maximal function associated to $ρ$ between Zygmund spaces of $L\,\log\,L$ type with $A_p$ weights.
