{
  "id": "math/0008203",
  "version": "v2",
  "published": "2000-08-27T16:50:17.000Z",
  "updated": "2001-07-23T13:49:41.000Z",
  "title": "What is missing in canonical models for proper normal algebraic surfaces?",
  "authors": [
    "Stefan Schroeer"
  ],
  "comment": "10 pages, minor changes, to appear in Abh. Math. Sem. Univ. Hamburg",
  "journal": "Abh. Math. Sem. Univ. Hamburg 71 (2001), 257-268.",
  "categories": [
    "math.AG"
  ],
  "abstract": "Smooth surfaces have finitely generated canonical rings and projective canonical models. For normal surfaces, however, the graded ring of multicanonical sections is possibly nonnoetherian, such that the corresponding homogeneous spectrum is noncompact. I construct a canonical compactification by adding finitely many non-Q-Gorenstein points at infinity, provided that each Weil divisor is numerically equivalent to a Q-Cartier divisor. Similar results hold for arbitrary Weil divisors instead of the canonical class.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2001-07-23T13:49:41.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "14C20",
      "14J17",
      "14J29"
    ],
    "keywords": [
      "proper normal algebraic surfaces",
      "canonical models",
      "arbitrary weil divisors",
      "similar results hold",
      "normal surfaces"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2000math......8203S"
    }
  }
}