2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/222533Kerr's manifold is only a Schwarzschild's manifold as seen by a suitably rotating coordinate system. By taking into account this fact, Kerr's manifold can be reduced to a Schwarzschild's manifold. In a final summary we give the main steps of our reasoning.6 pages, LaTeXGeneral Physicstext