2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/196735If the equation of state for "dark energy" varies periodically, the expansion of the Universe may have undergone alternating eras of acceleration and deceleration. We examine a specific form that survives existing observational tests, does not single out the present state of the Universe as exceptional, and suggests a future much like the matter-dominated past: a smooth expansion without a final inflationary epoch.4 pages, 4 figures, uses RevTeXAstrophysicsHigh Energy Physics - Phenomenologytext