{
  "id": "math/0507175",
  "version": "v1",
  "published": "2005-07-08T12:47:17.000Z",
  "updated": "2005-07-08T12:47:17.000Z",
  "title": "Specialization of $F$-Zips",
  "authors": [
    "Torsten Wedhorn"
  ],
  "comment": "23 pages",
  "categories": [
    "math.AG",
    "math.RT"
  ],
  "abstract": "In \\cite{MW}, 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.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2005-07-08T12:47:17.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "14G35",
      "14F40",
      "14K10",
      "11G15",
      "20G40",
      "20F55"
    ],
    "keywords": [
      "specialization",
      "explicit combinatorial recipe",
      "moduli space",
      "ekedahl-oort strata",
      "closure relation"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 23,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2005math......7175W"
    }
  }
}