$A_p$-$A_\infty$ estimates for multilinear maximal and sparse operators

TL;DR

This paper establishes new mixed $A_p$--$A_$ estimates for a broad class of multilinear maximal and sparse operators, enhancing understanding of their control over various classical operators in harmonic analysis.

Contribution

It introduces a multilinear version of the Fujii--Wilson $A_$ characteristic, enabling improved mixed characteristic estimates for multilinear operators.

Findings

Derived mixed $A_p$--$A_$ estimates for multilinear operators.

Unified control over Calderf3n--Zygmund operators, square functions, and fractional integrals.

Recovered best known estimates for dependent weights as special cases.

Abstract

We obtain mixed $A_p$--$A_\infty$ estimates for a large family of multilinear maximal and sparse operators. Operators from this family are known to control for instance multilinear Calder\'on--Zygmund operators, square functions, fractional integrals, and the bilinear Hilbert transform. Our results feature a new multilinear version of the Fujii--Wilson $A_\infty$ characteristic that allows us to recover the best known estimates in terms of the $A_p$ characteristic for dependent weights as a special case of the mixed characteristic estimates for general tuples of weights.