2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/51855We will review the algebras which have been conjectured as symmetries in M-theory. The Borcherds algebras, which are the most general Lie algebras under control, seem natural candidates.6 pages, talk given by PHL at Cargese 2002High Energy Physics - Theorytext