A GENERALIZATION OF CHENG'S THEOREM ∗
A GENERALIZATION OF CHENG'S THEOREM ∗
复制标题
程定理的推广 *
DOI:
--
复制
发表时间:
2008
期刊:
影响因子:
--
通讯作者:
Jiaping Wang
中科院分区:
文献类型:
--
作者:
Peter Li;Jiaping Wang
0. Introduction. In this paper, we prove a generalization of a theorem of S.Y. Cheng on the upper bound of the bottom of the L spectrum for a complete Riemannian manifold. In [C], Cheng proved a comparison theorem for the first Dirichlet eigenvalue of a geodesic ball. By taking the radius of the ball to infinity, he obtained an estimate for the bottom of the L spectrum. In particular, he showed that if M is an n-dimensional complete Riemannian manifold whose Ricci curvature is bounded from below by −(n− 1)K for some constant K > 0, then the bottom of the L spectrum, λ1(M), is bounded by λ1(M) ≤ (n− 1)K 4 .