{ "id": "2004.08988", "version": "v1", "published": "2020-04-19T23:16:55.000Z", "updated": "2020-04-19T23:16:55.000Z", "title": "Neccessary conditions for two weight inequalities for singular integral operators", "authors": [ "David Cruz-Uribe", "John-Oliver MacLellan" ], "categories": [ "math.CA" ], "abstract": "We prove necessary conditions on pairs of measures $(\\mu,\\nu)$ for a singular integral operator $T$ to satisfy weak $(p,p)$ inequalities, $1\\leq p<\\infty$, provided the kernel of $T$ satisfies a weak non-degeneracy condition first introduced by Stein, and the measure $\\mu$ satisfies a weak doubling condition related to the non-degeneracy of the kernel. We also show similar results for pairs of measures $(\\mu,\\sigma)$ for the operator $T_\\sigma f = T(f\\,d\\sigma)$, which has come to play an important role in the study of weighted norm inequalities. Our major tool is a careful analysis of the strong type inequalities for averaging operators; these results are of interest in their own right. Finally, as an application of our techniques, we show that in general a singular operator does not satisfy the endpoint strong type inequality $T : L^1(\\nu) \\rightarrow L^1(\\mu)$. Our results unify and extend a number of known results.", "revisions": [ { "version": "v1", "updated": "2020-04-19T23:16:55.000Z" } ], "analyses": { "subjects": [ "42B20", "42B35" ], "keywords": [ "singular integral operator", "weight inequalities", "neccessary conditions", "endpoint strong type inequality", "weak non-degeneracy condition first" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }