{ "id": "1409.8070", "version": "v1", "published": "2014-09-29T10:59:33.000Z", "updated": "2014-09-29T10:59:33.000Z", "title": "Codimension formulae for the intersection of fractal subsets of Cantor spaces", "authors": [ "Casey Donoven", "Kenneth Falconer" ], "categories": [ "math.MG" ], "abstract": "We examine the dimensions of the intersection of a subset $E$ of an $m$-ary Cantor space $\\mathcal{C}^m$ with the image of a subset $F$ under a random isometry with respect to a natural metric. We obtain almost sure upper bounds for the Hausdorff and upper box-counting dimensions of the intersection, and a lower bound for the essential supremum of the Hausdorff dimension. The dimensions of the intersections are typically $\\max\\{\\dim E +\\dim F -\\dim \\mathcal{C}^m, 0\\}$, akin to other codimension theorems. The upper estimates come from the expected sizes of coverings, whilst the lower estimate is more intricate, using martingales to define a random measure on the intersection to facilitate a potential theoretic argument.", "revisions": [ { "version": "v1", "updated": "2014-09-29T10:59:33.000Z" } ], "analyses": { "subjects": [ "28A80", "20E08", "60G57" ], "keywords": [ "intersection", "codimension formulae", "fractal subsets", "ary cantor space", "potential theoretic argument" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1409.8070D" } } }