2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/75516Let G be a connected semisimple linear algebraic group over an algebraically closed field k of positive characteristic and let X denote an equivariant embedding of G. We define a distinguished Steinberg fiber N in G, called the zero-fiber, and prove that the closure of N within X is normal and Cohen-Macaulay. Furthermore, when X is smooth we prove that the closure of N is a local complete intersection.18 pagesAlgebraic GeometryRepresentation Theory14M17; 13A35text