%0 Journal Article
%T Plane domains which are spectrally determined II
%A Watanabe Kohtaro
%J Journal of Inequalities and Applications
%D 2002
%I Springer
%X Existence of the non-disk plane domains, which are determined from Dirichlet (or Neumann) spectrum of the Laplacian, is proved. It is shown that these domains are oval which have just four vertices when , where denotes an area and a boundary length of a domain.
%K Trace of the heat kernel
%K Planar drum problem
%K Eigenvalues of the Laplacian
%U http://www.journalofinequalitiesandapplications.com/content/7/613103