Symmetry, Singularities and Integrability in Complex Dynamics IV: Painleve Integrability of Isotropic Cosmologies

We 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 Painlev\'{e} test is sufficient to demonstrate integrability or nonintegrability in the sense of Painlev\'{e}. For others of these models it is necessary to use a less algorithmic procedure.