{ "id": "1402.2799", "version": "v4", "published": "2014-02-12T12:18:16.000Z", "updated": "2014-04-21T10:52:03.000Z", "title": "Rectifiability via a square function and Preiss' theorem", "authors": [ "Xavier Tolsa", "Tatiana Toro" ], "comment": "Minor corrections and adjustments", "categories": [ "math.CA", "math.AP" ], "abstract": "Let $E$ be a set in $\\mathbb R^d$ with finite $n$-dimensional Hausdorff measure $H^n$ such that $\\liminf_{r\\to0}r^{-n} H^n(B(x,r)\\cap E)>0$ for $H^n$-a.e. $x\\in E$. In this paper it is shown that $E$ is $n$-rectifiable if and only if $$\\int_0^1 \\left|\\frac{H^n(B(x,r)\\cap E)}{r^n} - \\frac{H^n(B(x,2r)\\cap E)}{(2r)^n}\\right|^2\\,\\frac{dr}r < \\infty$$ for $H^n$-a.e. $x\\in E$; and also if and only if $$ \\lim_{r\\to0}\\left(\\frac{H^n(B(x,r)\\cap E)}{r^n} - \\frac{H^n(B(x,2r)\\cap E)}{(2r)^n}\\right) = 0$$ for $H^n$-a.e. $x\\in E$. Other more general results involving Radon measures are also proved.", "revisions": [ { "version": "v4", "updated": "2014-04-21T10:52:03.000Z" } ], "analyses": { "subjects": [ "28A75", "28A78", "42B20" ], "keywords": [ "square function", "rectifiability", "dimensional hausdorff measure", "radon measures" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1402.2799T" } } }