{ "id": "math-ph/0703020", "version": "v1", "published": "2007-03-05T20:11:05.000Z", "updated": "2007-03-05T20:11:05.000Z", "title": "On the critical exponent in an isoperimetric inequality for chords", "authors": [ "Pavel Exner", "Martin Fraas", "Evans M. Harrell II" ], "comment": "LaTeX, 12 pages, with 1 eps figure", "doi": "10.1016/j.physleta.2007.03.067", "categories": [ "math-ph", "math.AC", "math.MP" ], "abstract": "The problem of maximizing the $L^p$ norms of chords connecting points on a closed curve separated by arclength $u$ arises in electrostatic and quantum--mechanical problems. It is known that among all closed curves of fixed length, the unique maximizing shape is the circle for $1 \\le p \\le 2$, but this is not the case for sufficiently large values of $p$. Here we determine the critical value $p_c(u)$ of $p$ above which the circle is not a local maximizer finding, in particular, that $p_c(\\frac12 L)=\\frac52$. This corrects a claim made in \\cite{EHL}.", "revisions": [ { "version": "v1", "updated": "2007-03-05T20:11:05.000Z" } ], "analyses": { "keywords": [ "isoperimetric inequality", "critical exponent", "closed curve", "chords connecting points", "unique maximizing shape" ], "tags": [ "journal article" ], "note": { "typesetting": "LaTeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable" } } }