On the range of the first two Dirichlet eigenvalues of the Laplacian with volume and perimeter constraint
Antunes, Pedro R. S.; Henrot, Antoine
Publ. RIMS, Kyoto University, 1850 (2013), 66-78
In this paper we study the set of points, in the plane
are the two rst eigenvalues of the Dirichlet-Laplacian. We give some qualitative properties of these sets and show some pictures obtained through numerical computations.