M. Chen et Fy. Wang, GENERAL FORMULA FOR LOWER-BOUND OF THE FIRST EIGENVALUE ON RIEMANNIAN-MANIFOLDS, Science in China. Series A, Mathematics, Physics, Astronomy & Technological Sciences, 40(4), 1997, pp. 384-394
A general formula for the lower bound of the first eigenvalue on compa
ct Riemannian manifolds is presented. The formula improves the main kn
own sharp estimates including Lichnerowicz's estimate and Zhong-Yang's
estimate. Moreover, the results are extended to the noncompact manifo
lds. The study is based on the probabilistic approach (i. e. the coupl
ing method).