2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/60426We investigate the bad reduction of certain Shimura varieties (associated to the symplectic group). More precisely, we look at a model of the Shimura variety at a prime p, with parahoric level structure at p. We show that this model is flat, as conjectured by Rapoport and Zink, and that its special fibre is reduced.31 pages, LaTeXAlgebraic Geometry14G35; 11G18text