{ "id": "0909.4696", "version": "v2", "published": "2009-09-25T16:21:15.000Z", "updated": "2009-09-28T13:15:32.000Z", "title": "Regularity of minimizers of semilinear elliptic problems up to dimension four", "authors": [ "Xavier Cabre" ], "categories": [ "math.AP" ], "abstract": "We consider the class of semi-stable solutions to semilinear equations $-\\Delta u=f(u)$ in a bounded smooth domain $\\Omega$ of $R^n$ (with $\\Omega$ convex in some results). This class includes all local minimizers, minimal, and extremal solutions. In dimensions $n \\leq 4$, we establish an priori $L^\\infty$ bound which holds for every positive semi-stable solution and every nonlinearity $f$. This estimate leads to the boundedness of all extremal solutions when $n=4$ and $\\Omega$ is convex. This result was previously known only in dimensions $n\\leq 3$ by a result of G. Nedev. In dimensions $5 \\leq n \\leq 9$ the boundedness of all extremal solutions remains an open question. It is only known to hold in the radial case $\\Omega=B_R$ by a result of A. Capella and the author.", "revisions": [ { "version": "v2", "updated": "2009-09-28T13:15:32.000Z" } ], "analyses": { "subjects": [ "35B45", "35J61" ], "keywords": [ "semilinear elliptic problems", "regularity", "semi-stable solution", "extremal solutions remains", "bounded smooth domain" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0909.4696C" } } }