{
  "id": "0901.2291",
  "version": "v1",
  "published": "2009-01-15T15:57:59.000Z",
  "updated": "2009-01-15T15:57:59.000Z",
  "title": "Strong subgroup chains and the Baer-Specker group",
  "authors": [
    "Oren Kolman"
  ],
  "comment": "12 pages",
  "journal": "Models, Modules and Abelian Groups, B. Goldsmith; R. G\\\"obel (Ed.) (2008) 189-200",
  "categories": [
    "math.LO",
    "math.GR"
  ],
  "abstract": "Examples are given of non-elementary properties that are preserved under C-filtrations for various classes C of Abelian groups. The Baer-Specker group is never the union of a chain of proper subgroups with cotorsionfree quotients. Cotorsion-free groups form an abstract elementary class (AEC). The Kaplansky invariants of the Baer-Specker group are used to determine the AECs defined by the perps of the Baer-Specker quotient groups that are obtained by factoring the Baer-Specker group B of a ZFC extension by the Baer-Specker group A of the ground model, under various hypotheses, yielding information about its stability spectrum.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2009-01-15T15:57:59.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "baer-specker group",
      "strong subgroup chains",
      "cotorsion-free groups form",
      "abstract elementary class",
      "baer-specker quotient groups"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}