2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/14219We show how the investigation of the redshifted 21-cm radiation can give insight into the development of structures in the early universe (at redshifts z>5). In particular we investigate: the epoch of the first light; the fluctuations in the redshifted 21-cm emission induced by the density inhomogeneities in CDM dominated universes; the emission and absorption shells that are generated around the first bright quasars. Such features can be observed with the next generation radio facilities.8 pages, including 7 figures, to appear in: Proc. 19th Texas Symposium on Relativistic Astrophysics and Cosmology, Paris, France, Dec. 1998Astrophysicstext