2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/189729Contrary to the expected behavior, we show the existence of non-invertible deformations of Lie algebras which can generate invariants for the coadjoint representation, as well as delete cohomology with values in the trivial or adjoint module. A criterion to decide whether a given deformation is invertible or not is given in dependence of the Poincaré polynomial.13 pages, 1 tableHigh Energy Physics - Theorytext