{ "id": "1609.08186", "version": "v1", "published": "2016-09-26T20:48:21.000Z", "updated": "2016-09-26T20:48:21.000Z", "title": "Extremal functions for Morrey's inequality in convex domains", "authors": [ "Ryan Hynd", "Erik Lindgren" ], "comment": "24 pages, 7 figures", "categories": [ "math.AP" ], "abstract": "For a bounded domain $\\Omega\\subset \\mathbb{R}^n$ and $p>n$, Morrey's inequality implies that there is $c>0$ such that $$ c\\|u\\|^p_{\\infty}\\le \\int_\\Omega|Du|^pdx $$ for each $u$ belonging to the Sobolev space $W^{1,p}_0(\\Omega)$. We show that the ratio of any two extremal functions is constant provided that $\\Omega$ is convex. We also explain why this property fails to hold in general and verify that convexity is not a necessary condition for a domain to have this property. As a by product, we obtain the uniqueness of an optimization problem involving the Green's function for the $p$-Laplacian.", "revisions": [ { "version": "v1", "updated": "2016-09-26T20:48:21.000Z" } ], "analyses": { "keywords": [ "extremal functions", "convex domains", "morreys inequality implies", "greens function", "optimization problem" ], "note": { "typesetting": "TeX", "pages": 24, "language": "en", "license": "arXiv", "status": "editable" } } }