2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/81539Discontinuities in relativistic hydrodynamics - shock waves and freeze-out shocks - are considered across both space-like and time-like hypersurfaces. We analyze the peculiar features of the freeze-out discontinuities and their connection to the shock-wave phenomena.11 pages, Proceedings of Conference ``Non-Euclidean Geometry in Modern Physics'', Nyiregyha'za, Hungary, July 7-10, 1999Nuclear Theorytext