The sharp upper bounds for the first positive eigenvalue of the Kohn-Laplacian on compact strictly pseudoconvex hypersurfaces
arXiv:1611.10001 · doi:10.1007/s00209-017-1922-z
Abstract
We give sharp and explicit upper bounds for the first positive eigenvalue of the Kohn-Laplacian on compact strictly pseudoconvex hypersurfaces in in terms of their defining functions. As an application, we show that in the family of real ellipsoids, has a unique maximum value at the CR sphere.
Final version, appears on Mathematische Zeitschrift