2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/164517We investigate Siegel modular varieties in positive characteristic with Iwahori level structure. On these spaces, we have the Newton stratification, and the Kottwitz-Rapoport stratification; one would like to understand how these stratifications are related to each other. We give a simple description of all KR strata which are entirely contained in the supersingular locus as disjoint unions of Deligne-Lusztig varieties. We also give an explicit numerical description of the KR stratification in terms of abelian varieties.v2: Minor corrections; explained relation to [Goertz,Yu, arXiv:0807.1229]; improved introductionAlgebraic GeometryNumber Theory14G35; 14K10; 11G18text