2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/52155We analyze the validity of the generalized covariant entropy bound near the apparent horizon of isotropic expanding cosmological models. We encounter violations of the bound for cosmic times smaller than a threshold. By introducing an infrared cutoff we are able to mantain the bound for a radiation dominated universe. We study different physical mechanisms to restore the bound, as a non-additivity of the entropy at a fundamental level and/or a cosmological uncertainty relation.9 pages, contribution to the proceedings of "String Phenomenology 2003" conference, Durham, UK, July 29-August 4High Energy Physics - TheoryGeneral Relativity and Quantum Cosmologytext