2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/95684Consequent application of the instantaneous approximation to both the interaction and all propagators of the bound-state constituents allows us to forge, within the framework of the Bethe-Salpeter formalism for the description of bound states, an instantaneous form of the Bethe-Salpeter equation with exact (i.e., full) propagators of the bound-state constituents. This instantaneous equation generalizes the well-known Salpeter equation the derivation of which needs the additional assumption of free propagation of the bound-state constituents.11 pagesHigh Energy Physics - TheoryHigh Energy Physics - PhenomenologyNuclear Theorytext