Castañeda, Nelson
Artículo de revista
Hessians
Warped products
Eigenvalue bounds
Riemannian manifold
We use the Hessian - Weitzenböck formula to simplify the exposition of several well known theorems. We present a uni ed treatment of the theorems of Lichnerowicz - Obata, Reilly and Escobar regarding the rst eigenvalue of the Laplacian on Manifolds.