Commutators of certain fractional type operators with hörmander conditions, one–weighted and two–weighted inequalities

Abstract

In this paper we study commutators of a certain class of fractional type integral operators. These operators are given by kernels of the form K(x,y) = k1(x−A1y)k2(x−A2y)...km(x−Amy), where Ai are invertible matrices and each ki satisfies a fractional size condition and generalized fractional Hörmander condition. We obtain weighted Coifman estimates and weighted Lp(wp) - Lq(wq) estimates. We also give a two-weighted strong type estimate for pairs of weights of the form (u,Su) where u is an arbitrary non-negative function and S is a maximal operator depending on the smoothness of the kernel K. For the singular case we also give a two-weighted endpoint estimate.