2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/50767I review some properties of D-branes in the SU(2) and SL(2,R) WZW models. I comment on a potential difficulty for the realization of `warped brane worlds' in string theory. This short note is based on a talk given at the Strings'01 conference in Mumbay.11 pages, Latex, 2 eps figures, uses JHEP.clsHigh Energy Physics - Theorytext