2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/96945The atom optics of Bose-Einstein condensates containing a vortex of circulation one is discussed. We first analyze in detail the reflection of such a condensate falling on an atomic mirror. In a second part, we consider a rotating condensate in the case of attractive interactions. We show that for sufficiently large nonlinearity the rotational symmetry of the rotating condensate is broken.7 pages, 7 figures, to be published in EPJ DSoft Condensed Mattertext