TY - JOUR T1 - The Problem of Eigenvalue on Noncompact Complete Riemannian Manifold AU - Li Jiayu JO - Journal of Partial Differential Equations VL - 4 SP - 87 EP - 95 PY - 1992 DA - 1992/05 SN - 5 DO - http://doi.org/ UR - https://global-sci.org/intro/article_detail/jpde/5756.html KW - Laplacian KW - spectrum KW - eigenvalue AB - Let M be an n-dimensional noncompact complete Riemannian manifold, "Δ" is the Laplacian of M. It is a negative selfadjoint operator in L²(M). First, we give a criterion of non-existence of eigenvalue by the heat kernel. Applying the criterion yields that the Laplacian on noncompact constant curvature space form has no eigenvalue. Then, we give a geometric condition of M under which the Laplacian of M has eigenvalues. It implies that changing the metric on a compact domain of constant negative curvature space form may yield eigenvalues.