2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/50971We discuss the possible existence of new generic vacuum solutions of Robertson-Walker form in higher derivative gravity theories in four dimensions. These solutions illustrate how a dynamical coupling between very low and very high frequency modes can occur when the cosmological constant is small.8 pages, 4 figuresHigh Energy Physics - TheoryHigh Energy Physics - Phenomenologytext