Upper and lower bounds for normal derivatives of spectral clusters of Dirichlet Laplacian
arXiv:1004.2517
Abstract
In this paper, we prove the upper and lower bounds for normal derivatives of spectral clusters of Dirichlet Laplacian , where the upper bound is true for any Riemannian manifold, and the lower bound is true for some small , where depends on the manifold only, provided that has no trapped geodesics (see Theorem \ref{Thm3} for a precise statement), which generalizes the early results for single eigenfunctions by Hassell and Tao.
14 pages, Rewrite section 6 (the appendix) and correct a mistake in section 6