2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/113977We prove that if A is an infinite von Neumann algebra (i. e., the identity can be decomposed as a sum of a sequence of pairwise disjoint projections, all equivalent to the identity) then the cyclic cohomology of A vanishes. We show that the method of the proof applies to certain algebras of infinite matrices.Operator AlgebrasK-Theory and Homology46M20; 46L10text