Saved in:
Bibliographic Details
Main Author: Perdices, Eduard Roure
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2404.09351
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866929313717157888
author Perdices, Eduard Roure
author_facet Perdices, Eduard Roure
contents We present a multi-variable extension of Rubio de Francia's restricted weak-type extrapolation theory that does not involve Rubio de Francia's iteration algorithm; instead, we rely on the following Sawyer-type inequality for the weighted Hardy-Littlewood maximal operator $M_u$: $$ \left \Vert \frac{M_u (fv)}{v} \right \Vert_{L^{1,\infty}(uv)} \leq C_{u,v} \Vert f \Vert_{L^1(uv)}, \quad u, \, uv \in A_{\infty}. $$ Our approach can be adapted to recover weak-type $A_{\vec P}$ extrapolation schemes, including an endpoint result that falls outside the classical theory. Among the applications of our work, we highlight extending outside the Banach range the well-known equivalence between restricted weak-type and weak-type for characteristic functions, and obtaining mixed and restricted weak-type bounds with $A_{p}^{\mathcal R}$ weights for relevant families of multi-variable operators, addressing the lack in the literature of these types of estimates. We also reveal several standalone properties of the class $A_{p}^{\mathcal R}$.
format Preprint
id arxiv_https___arxiv_org_abs_2404_09351
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Extrapolation via Sawyer-type inequalities
Perdices, Eduard Roure
Functional Analysis
Classical Analysis and ODEs
42B25 (Primary), 46E30 (Secondary)
We present a multi-variable extension of Rubio de Francia's restricted weak-type extrapolation theory that does not involve Rubio de Francia's iteration algorithm; instead, we rely on the following Sawyer-type inequality for the weighted Hardy-Littlewood maximal operator $M_u$: $$ \left \Vert \frac{M_u (fv)}{v} \right \Vert_{L^{1,\infty}(uv)} \leq C_{u,v} \Vert f \Vert_{L^1(uv)}, \quad u, \, uv \in A_{\infty}. $$ Our approach can be adapted to recover weak-type $A_{\vec P}$ extrapolation schemes, including an endpoint result that falls outside the classical theory. Among the applications of our work, we highlight extending outside the Banach range the well-known equivalence between restricted weak-type and weak-type for characteristic functions, and obtaining mixed and restricted weak-type bounds with $A_{p}^{\mathcal R}$ weights for relevant families of multi-variable operators, addressing the lack in the literature of these types of estimates. We also reveal several standalone properties of the class $A_{p}^{\mathcal R}$.
title Extrapolation via Sawyer-type inequalities
topic Functional Analysis
Classical Analysis and ODEs
42B25 (Primary), 46E30 (Secondary)
url https://arxiv.org/abs/2404.09351