2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/61283We prove a new lower bound for the first eigenvalue of the Dirac operator on a compact Riemannian spin manifold by refined Weitzenböck techniques. It applies to manifolds with harmonic curvature tensor and depends on the Ricci tensor. Examples show how it behaves compared to other known bounds.Latex2.09, 15 pagesDifferential Geometry53C27, 53C25text