{ "id": "1907.09895", "version": "v1", "published": "2019-07-23T14:12:32.000Z", "updated": "2019-07-23T14:12:32.000Z", "title": "On the number of critical points of solutions of semilinear equations in $\\mathbb{R}^2$", "authors": [ "Francesca Gladiali", "Massimo Grossi" ], "categories": [ "math.AP" ], "abstract": "In this paper we construct families of domains $\\Omega_\\varepsilon$ and solutions $u_\\varepsilon$ of \\[\\begin{cases} -\\Delta u_\\varepsilon=1&\\text{ in }\\ \\Omega_\\varepsilon\\\\ u_\\varepsilon=0&\\text{ on }\\ \\partial\\Omega_\\varepsilon \\end{cases}\\] such that, for any integer $k\\ge2$, $u_\\varepsilon$ admits at least $k$ maxima points. The domain $\\Omega_\\varepsilon$ is \"not far\" to be convex in the sense that it is starshaped, the curvature of $\\partial\\Omega_\\varepsilon$ changes sign $once$ and the minimum of the curvature of $\\partial\\Omega_\\varepsilon$ goes to $0$ as $\\varepsilon\\to0$. Extensions to more general nonlinear elliptic problems will be provided.", "revisions": [ { "version": "v1", "updated": "2019-07-23T14:12:32.000Z" } ], "analyses": { "keywords": [ "semilinear equations", "critical points", "general nonlinear elliptic problems", "changes sign", "construct families" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }