Burdzy, Krzysztof2005-10-142005-10-142005Duke Mathematical Journalhttp://hdl.handle.net/1773/2132There exists a planar domain with piecewise smooth boundary and one hole such that the second eigenfunction for the Laplacian with Neumann boundary conditions attains its maximum and minimum inside the domain.198331 bytesapplication/pdfen-USNeumann LaplacianNeumann eigenfunctionsArticle