{ "id": "2310.07538", "version": "v1", "published": "2023-10-11T14:41:20.000Z", "updated": "2023-10-11T14:41:20.000Z", "title": "Hausdorff dimension of plane sections and general intersections", "authors": [ "Pertti Mattila" ], "comment": "10 pages. arXiv admin note: substantial text overlap with arXiv:2005.11790", "categories": [ "math.CA" ], "abstract": "This paper extends some results of [M5] and [M3], in particular, removing assumptions of positive lower density. We give conditions on a general family $P_{\\lambda}:\\mathbb{R}^{n}\\to\\mathbb{R}^{m}, \\lambda \\in \\Lambda,$ of orthogonal projections which guarantee that the Hausdorff dimension formula $\\dim A\\cap P_{\\lambda}^{-1}\\{u\\}=s-m$ holds generically for measurable sets $A\\subset\\mathbb{R}^{n}$ with positive and finite $s$-dimensional Hausdorff measure, $s>m$. As an application we prove for measurable sets $A,B\\subset\\mathbb{R}^{n}$ with positive $s$- and $t$-dimensional measures that if $s + (n-1)t/n > n$, then $\\dim A\\cap (g(B)+z) \\geq s+t - n$ for almost all rotations $g$ and for positively many $z\\in\\mathbb{R}^{n}$. We shall also give an application on the estimates of the dimension of the set of exceptional rotations.", "revisions": [ { "version": "v1", "updated": "2023-10-11T14:41:20.000Z" } ], "analyses": { "keywords": [ "general intersections", "plane sections", "dimensional hausdorff measure", "measurable sets", "hausdorff dimension formula" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable" } } }