2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/142873We prove that a four-dimensional Lorentzian manifold that is curvature homogeneous of order 3, or $\CH_3$ for short, is necessarily locally homogeneous. We also exhibit and classify four-dimensional Lorentzian, $\CH_2$ manifolds that are not homogeneous.8 pagesGeneral Relativity and Quantum CosmologyDifferential Geometrytext