2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/33685We apply the results of singularity analysis to the isotropic cosmological models in general relativity and string theory with a variety of matter terms. For some of these models the standard Painlevé test is sufficient to demonstrate integrability or nonintegrability in the sense of Painlevé. For others of these models it is necessary to use a less algorithmic procedure.9 pp, latex, gc style, to appear in Grav.CosmGeneral Relativity and Quantum Cosmologytext