Weighted norm estimates of noncommutative Calderón-Zygmund operators
Wenfei Fan, Yong Jiao, Lian Wu, Dejian Zhou
TL;DR
This work develops the weighted endpoint theory for operator-valued Calderón-Zygmund operators in a noncommutative setting. It proves weighted weak-type bounds for noncommutative maximal CZ operators, establishes weighted square-function estimates, and derives a weighted $H_1-L_1$ inequality under $A_1$ weights and regularity conditions weaker than Lipschitz, leveraging a refined noncommutative CZ decomposition and a new weighted atomic theory for martingales. The approach combines lacunary reductions, kernel regularity in $\mathcal{H}_{2r_w'}$, and weighted atomic decompositions to extend unweighted and commutative results to the weighted noncommutative context, with applications to operator-valued harmonic analysis. These results broaden the scope of weighted inequalities in noncommutative harmonic analysis and pave the way for weighted martingale inequalities in operator-valued settings.
Abstract
This paper is devoted to studying weighted endpoint estimates of operator-valued singular integrals. Our main results include weighted weak-type $(1,1)$ estimate of noncommutative maximal Calderón-Zygmund operators, corresponding version of square functions and a weighted $H_1- L_1$ type inequality. All these results are obtained under the condition that the weight belonging to the Muchenhoupt $A_1$ class and certain regularity assumptions imposed on kernels which are weaker than the Lipschitz condition.
