{ "id": "1412.2593", "version": "v1", "published": "2014-12-08T14:52:11.000Z", "updated": "2014-12-08T14:52:11.000Z", "title": "Two-weight $L^p$-$L^q$ bounds for positive dyadic operators: unified approach to $p\\leq q$ and $p>q$", "authors": [ "Timo S. Hänninen", "Tuomas P. Hytönen", "Kangwei Li" ], "comment": "27 pages", "categories": [ "math.CA" ], "abstract": "We characterize the $L^p(\\sigma)\\to L^q(\\omega)$ boundedness of positive dyadic operators of the form $ T(f\\sigma)=\\sum_{Q\\in\\mathscr{D}}\\lambda_Q\\int_Q f\\,\\mathrm{d}\\sigma\\cdot 1_Q, $ and the $L^{p_1}(\\sigma_1)\\times L^{p_2}(\\sigma_2)\\to L^q(\\omega)$ boundedness of their bilinear analogues, for arbitrary locally finite measures $\\sigma,\\sigma_1,\\sigma_2,\\omega$. In the linear case, we unify the existing \"Sawyer testing\" (for $p\\leq q$) and \"Wolff potential\" (for $p>q$) characterizations into a new \"sequential testing\" characterization valid in all cases. We extend these ideas to the bilinear case, obtaining both sequential testing and potential type characterizations for the bilinear operator and all $p_1,p_2,q\\in(1,\\infty)$. Our characterization covers the previously unknown case $q<\\frac{p_1p_2}{p_1+p_2}$, where we introduce a new two-measure Wolff potential.", "revisions": [ { "version": "v1", "updated": "2014-12-08T14:52:11.000Z" } ], "analyses": { "subjects": [ "42B25", "47G40" ], "keywords": [ "positive dyadic operators", "unified approach", "two-weight", "two-measure wolff potential", "potential type characterizations" ], "note": { "typesetting": "TeX", "pages": 27, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1412.2593H" } } }