2005/07/08 by Torsten Wedhorn, Wedhorn, Torsten
Mathematics · #11G15 #14F40 #14G35 #14K10 #20F55 #20G40 #Advanced Algebra and Geometry #Advanced Combinatorial Mathematics #Algebraic Geometry (math.AG) #Algebraic Geometry and Number Theory #FOS: Mathematics #Representation Theory (math.RT) #math.AG #math.RT #msc:11G15 #msc:14F40 #msc:14G35 #msc:14K10 #msc:20F55 #msc:20G40
paper · pdf · doi:10.48550/arxiv.math/0507175
23 pages
arxiv created 2005/07/08 · openalex publication_date 2005/07/08 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In \citeMW, B. Moonen and the author defined a new invariant, called F-Zips, of certain varieties in positive characteristics. We showed that the isomorphism classes of these invariants can be interpreted as orbits of a certain variety Z with an action of a reductive group G. In loc. cit. we gave a combinatorial description of the set of these orbits. In this manuscript we give an explicit combinatorial recipe to decide which orbits are in the closure of a given orbit. We do this by relating Z to a semi-linear variant of the wonderful compactification of G constructed by de Concini and Procesi. As an application we give an explicit criterion of the closure relation for Ekedahl-Oort strata in the moduli space of principally polarized abelian varieties.