2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/99919We give a new proof of the base change fundamental lemma for GL_n for certain Hecke functions by comparing the cohomology of two different moduli space of $D$-shtukas. The original proof, due to Clozel and Labesse, make use of the trace formula and of the unit case due to Kottwitz.published versionAlgebraic GeometryRepresentation Theory11G09 ; 11R39text