{ "id": "1904.03905", "version": "v1", "published": "2019-04-08T09:30:43.000Z", "updated": "2019-04-08T09:30:43.000Z", "title": "A monotonicity result under symmetry and Morse index constraints in the plane", "authors": [ "Francesca Gladiali" ], "categories": [ "math.AP" ], "abstract": "This paper deals with solutions of semilinear elliptic equations of the type \\[ \\left\\{\\begin{array}{ll} -\\Delta u = f(|x|, u) \\qquad & \\text{ in } \\Omega, \\\\ u= 0 & \\text{ on } \\partial \\Omega, \\end{array} \\right. \\] where $\\Omega$ is a radially symmetric domain of the plane that can be bounded or unbounded. We consider solutions $u$ that are invariant by rotations of a certain angle $\\theta$ and which have a bound on their Morse index in spaces of functions invariant by these rotations. We can prove that or $u$ is radial, or, else, there exists a direction $e\\in \\mathcal S$ such that $u$ is symmetric with respect to $e$ and it is strictly monotone in the angular variable in a sector of angle $\\frac{\\theta}2$. The result applies to least-energy and nodal least-energy solutions in spaces of functions invariant by rotations and produces multiplicity results.", "revisions": [ { "version": "v1", "updated": "2019-04-08T09:30:43.000Z" } ], "analyses": { "keywords": [ "morse index constraints", "monotonicity result", "functions invariant", "semilinear elliptic equations", "nodal least-energy solutions" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }