2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/33356We investigate the cross ratio for closed negatively curved manifolds. As one of several applications, we obtain that for two such homotopy equivalent manifolds M and N, the following is true : If M and N have the same marked length spectrum and if the Anosov splitting for M is C^1 then M and N have the same volume.33 pages, TexDifferential Geometrytext