{ "id": "1503.04008", "version": "v1", "published": "2015-03-13T10:20:24.000Z", "updated": "2015-03-13T10:20:24.000Z", "title": "The $L(\\log L)^ε$ endpoint estimate for maximal singular integral operators", "authors": [ "Tuomas Hytönen", "Carlos Pérez" ], "comment": "21 pages, final version, accepted for publication in J. Math. Anal. Appl", "categories": [ "math.CA" ], "abstract": "We prove in this paper the following estimate for the maximal operator $T^*$ associated to the singular integral operator $T$: $ \\|T^*f\\|_{L^{1,\\infty}(w)} \\lesssim \\frac{1}{\\epsilon} \\int_{\\mathbb{R}^n} |f(x)| M_{L(\\log L)^{\\epsilon}} (w)(x)dx$, for $w\\geq 0, 0<\\epsilon \\leq 1.$ This follows from the sharp $L^p$ estimate $ \\|T^*f \\|_{ L^{p}(w) } \\lesssim p' (\\frac{1}{\\delta})^{1/p'} \\|f \\|_{L^{p}(M_{ L(\\log L)^{p-1+\\delta}} (w))}$, for $1