2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/36043The problems causality and causality violation in topologically nontrivial space-time models are considered. To this end the mixed boundary problem for traversable wormhole models is formulated and the influence of the boundary conditions on the causal properties of space-time is analyzed3 pages, LaTex. Submitted to the Proc. of MG8 ConferenceGeneral Relativity and Quantum Cosmologytext