{ "id": "0912.1356", "version": "v2", "published": "2009-12-07T22:05:36.000Z", "updated": "2012-01-06T23:20:31.000Z", "title": "How to take shortcuts in Euclidean space: making a given set into a short quasi-convex set", "authors": [ "Jonas Azzam", "Raanan Schul" ], "comment": "Made referee edits", "doi": "10.1112/plms/pds005", "categories": [ "math.MG", "math.CA" ], "abstract": "For a given connected set $\\Gamma$ in $d-$dimensional Euclidean space, we construct a connected set $\\tilde\\Gamma\\supset \\Gamma$ such that the two sets have comparable Hausdorff length, and the set $\\tilde\\Gamma$ has the property that it is quasiconvex, i.e. any two points $x$ and $y$ in $\\tilde\\Gamma$ can be connected via a path, all of which is in $\\tilde\\Gamma$, which has length bounded by a fixed constant multiple of the Euclidean distance between $x$ and $y$. Thus, for any set $K$ in $d-$dimensional Euclidean space we have a set $\\tilde\\Gamma$ as above such that $\\tilde\\Gamma$ has comparable Hausdorff length to a shortest connected set containing $K$. Constants appearing here depend only on the ambient dimension $d$. In the case where $\\Gamma$ is Reifenberg flat, our constants are also independent the dimension $d$, and in this case, our theorem holds for $\\Gamma$ in an infinite dimensional Hilbert space. This work closely related to $k-$spanners, which appear in computer science. Keywords: chord-arc, quasiconvex, k-spanner, traveling salesman.", "revisions": [ { "version": "v2", "updated": "2012-01-06T23:20:31.000Z" } ], "analyses": { "subjects": [ "28A75" ], "keywords": [ "short quasi-convex set", "dimensional euclidean space", "connected set", "comparable hausdorff length", "infinite dimensional hilbert space" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0912.1356A" } } }