2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/107589In this paper we present some compactness results, showing how they can be applied in dealing with "zero mass" problems by a variational approach. In particular we use our results in two different situations: we look for complex valued solutions of a very classical elliptic equation, and we study an elliptic problem on an axially symmetric unbounded domain.28 pagesAnalysis of PDEs35Q55; 35J60text