{ "id": "2401.12112", "version": "v1", "published": "2024-01-22T16:50:23.000Z", "updated": "2024-01-22T16:50:23.000Z", "title": "A quantitative version of the Steinhaus theorem", "authors": [ "Alex Iosevich", "Jonathan Pakianathan" ], "categories": [ "math.CA" ], "abstract": "The classical Steinhaus theorem (\\cite{Steinhaus1920}) says that if $A \\subset {\\Bbb R}^d$ has positive Lebesgue measure than $A-A=\\{x-y: x,y \\in A\\}$ contains an open ball. We obtain some quantitative lower bounds on the size of this ball and in some cases, relate it to natural geometric properties of $\\partial A$. We also study the process $K_n =\\frac{1}{2}(K_{n-1} - K_{n-1})$ when $K_0$ is a compact subset of $\\mathbb{R}^d$ and determine various aspects of its convergence to $Conv(K_1)$, the convex hull of $K_1$. We discuss some connections with convex geometry, Weyl tube formula and the Kakeya needle problem. \\noindent {\\it Keywords: Measure theory, Steinhaus theorem, Convex geometry, Weyl tube formula.} \\noindent 2020 {\\it Mathematics Subject Classification:} Primary: 28A75, 52A27. Secondary: 52A30, 53A07.", "revisions": [ { "version": "v1", "updated": "2024-01-22T16:50:23.000Z" } ], "analyses": { "subjects": [ "28A75", "52A27", "52A30", "53A07" ], "keywords": [ "steinhaus theorem", "quantitative version", "weyl tube formula", "convex geometry", "kakeya needle problem" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }