2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/117859The aim of this work is to generalize Johnson's techniques in order to apply them to establish a bijective correspondence between $S$-derivations and continuous derivations on $M_a(S,ω),$ where $S$ is a locally compact foundation semigroup with identity $e$, and $ω$ is a weight function on $S$, and apply it to find a necessary condition for amenability of weighted group algebras.12 pagesFunctional Analysis46H25text