An overview on constrained critical points of Dirichlet integrals
arXiv:1907.00882
Abstract
We consider a natural generalization of the eigenvalue problem for the Laplacian with homogeneous Dirichlet boundary conditions. This corresponds to look for the critical values of the Dirichlet integral, constrained to the unit sphere. We collect some results, present some counter-examples and compile a list of open problems.
41 pages, 5 figures. This paper evolved from a set of notes for a talk delivered by the first author at the workshop "Nonlinear Meeting in Turin 2019"