2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/96569We show that anisotropic Bianchi type-IX models, with matter and cosmological constant have chaotic dynamics, connected to the presence of a saddle-center in phase space. The topology of cylinders emanating from unstable periodic orbits about the saddle-center provides an invariant characterization of chaos in the models. The model can be thought to describe the early stages of inflation, the way out to inflation being chaotic.3 pages, Latex (mprocl.sty), 4 figures. To appear in the proceedings of the Eighth Marcel Grossmann Meeting, Jerusalem, June 1997General Relativity and Quantum Cosmologytext