Speakers: Dan Mangoubi (Hebrew University)

Title: Multiplicity bounds for eigenvalues of the clamped circular plate.

Abstract: Consider a vibrating circular membrane with its (Dirichlet) Laplacian eigenvalues. Bourget's hypothesis, proved by Siegel in 1929, says that there are no eigenvalues of non-trivial multiplicities. On the other hand, it is an open question whether there are non-trivial multiplicities in the vibrating clamped circular plate problem. I will report on progress in this direction where it is shown that   no eigenvalue of the clamped circular plate has  multiplicity greater than four.

Based on joint work with Daniel Rosenblatt.