2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/34368The possibility that the dark energy may be described by the Chaplygin gas is discussed. Some observational constraints are established. These observational constraints indicate that a unified model for dark energy and dark matter through the employement of the Chaplygin gas is favored.5 pages, 2 EPS figures, LaTeX 2e, uses graphicx. To appear in the Proceedings of the XVIII IAP Colloquium `On the nature of dark energy', IAP, Paris, 1-5 July 2002General Relativity and Quantum Cosmologytext