2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/141190Several new characterizations of Banach spaces containing a subspace isomorphic to $\ell^1$, are obtained. These are applied to the question of when $\ell^1$ embeds in the injective tensor product of two Banach spaces.27 pages, AMSLaTeXFunctional Analysistext