2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/34090In this talk work done by our group on cosmic topology is reviewed. It ranges from early attempts to solve a famous controversy about quasars through the multiplicity of images, to quantum cosmology in this context and an application to QED renormalization.4 pages. Contribution to the XXII Brazilian National Meeting on Particles and Fields, Sao Lourenco, October 2001General Relativity and Quantum CosmologyAstrophysicsHigh Energy Physics - Theorytext