Affiliation: | Mathematics Laboratories, Graduate School of Information Sciences, Tohoku University, Katahira, Sendai, 980-8577, Japan Hajime Urakawa ; Mathematics Laboratories, Graduate School of Information Sciences, Tohoku University, Katahira, Sendai, 980-8577, Japan |
Abstract: | We prove two first eigenvalue pinching theorems for Riemannian symmetric spaces (Theorems 1 and 2). As their application, we answer negatively a question raised by Elworthy and Rosenberg, who proposed to show that for every compact simple Lie group with a bi-invariant Riemannian metric on with respect to , being the Killing form of the Lie algebra , the first eigenvalue would satisfy ![begin{equation*}sum _{j=1}^{2}sum _{ell =3}^{n} |[v_{j},v_{ell }]|^{2}>n(2lambda _{1}(h)-1),end{equation*}](http://www.ams.org/proc/1998-126-10/S0002-9939-98-04360-3/gif-abstract/img8.gif)
for all orthonormal bases of tangent spaces of (cf. Corollary 3). This problem arose in an attempt to give a spectral geometric proof that for a Lie group . |