{ "id": "1405.3428", "version": "v1", "published": "2014-05-14T09:50:39.000Z", "updated": "2014-05-14T09:50:39.000Z", "title": "Qualitative properties and classification of nonnegative solutions to $-Δu=f(u)$ in unbounded domains when $f(0)<0$", "authors": [ "Alberto Farina", "Berardino Sciunzi" ], "categories": [ "math.AP" ], "abstract": "We consider nonnegative solutions to $-\\Delta u=f(u)$ in unbounded euclidean domains, where $f$ is merely locally Lipschitz continuous and satisfies $f(0)<0$. In the half-plane, and without any other assumption on $u$, we prove that $u$ is either one-dimensional and periodic or positive and strictly monotone increasing in the direction orthogonal to the boundary. Analogous results are obtained if the domain is a strip. As a consequence of our main results, we answer affirmatively to a conjecture and to an open question posed by Berestycki, Caffarelli and Nirenberg. We also obtain some symmetry and monotonicity results in the higher-dimensional case.", "revisions": [ { "version": "v1", "updated": "2014-05-14T09:50:39.000Z" } ], "analyses": { "keywords": [ "nonnegative solutions", "qualitative properties", "unbounded domains", "classification", "direction orthogonal" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1405.3428F" } } }