2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/109332We consider the Landau-Zener problem for a Bose-Einstein condensate in a linearly varying two-level system, for the full many-particle system as well and in the mean-field approximation. The many-particle problem can be solved approximately within an independent crossings approximation, which yields an explicit Landau-Zener formula.RevTeX, 8 pages, 9 figuresQuantum Physicstext