2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/212550We study the problem of the existence of unconditional basic sequences in Banach spaces of high density. We show, in particular, the relative consistency with GCH of the statement that every Banach space of density $\aleph_ω$ contains an unconditional basic sequence.Functional AnalysisLogic46B03, 03E35text