{ "id": "1710.00451", "version": "v1", "published": "2017-10-02T01:42:58.000Z", "updated": "2017-10-02T01:42:58.000Z", "title": "Regularity for Shape Optimizers: The Degenerate Case", "authors": [ "Dennis Kriventsov", "Fanghua Lin" ], "categories": [ "math.AP" ], "abstract": "We consider minimizers of \\[ F(\\lambda_1(\\Omega),\\ldots,\\lambda_N(\\Omega)) + |\\Omega|, \\] where $F$ is a function nondecreasing in each parameter, and $\\lambda_k(\\Omega)$ is the $k$-th Dirichlet eigenvalue of $\\Omega$. This includes, in particular, functions $F$ which depend on just some of the first $N$ eigenvalues, such as the often studied $F=\\lambda_N$. The existence of a minimizer, which is also a bounded set of finite perimeter, was shown recently. Here we show that the reduced boundary of the minimizers $\\Omega$ is made up of smooth graphs, and examine the difficulties in classifying the singular points. Our approach is based on an approximation (\"vanishing viscosity\") argument, which--counterintuitively--allows us to recover an Euler-Lagrange equation for the minimizers which is not otherwise available.", "revisions": [ { "version": "v1", "updated": "2017-10-02T01:42:58.000Z" } ], "analyses": { "subjects": [ "49R05", "49N60", "35R35" ], "keywords": [ "degenerate case", "shape optimizers", "regularity", "th dirichlet eigenvalue", "finite perimeter" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }