2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/176737A class of Einstein-dilaton-axion models is found for which almost all flat expanding homogeneous and isotropic universes undergo recurrent periods of acceleration. We also extend recent results on eternally accelerating open universes.8 pages, 7 figures. minor changes. Version 4 corrects a figure captionHigh Energy Physics - TheoryAstrophysicsGeneral Relativity and Quantum Cosmologytext