2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/152420In this paper we discuss some topics related to the general theory of frames. In particular we focus our attention to the existence of different 'reconstruction formulas' for a given vector of a certain Hilbert space and to some refinement of the perturbative approach for the computation of the dual frame.LaTeX v2.09. In press in Nuovo Cimento BFunctional Analysistext