{
  "id": "1511.08930",
  "version": "v1",
  "published": "2015-11-28T21:11:09.000Z",
  "updated": "2015-11-28T21:11:09.000Z",
  "title": "Formality of 7-dimensional 3-Sasakian manifolds",
  "authors": [
    "Marisa Fernández",
    "Stefan Ivanov",
    "Vicente Muñoz"
  ],
  "comment": "10 pages",
  "categories": [
    "math.DG"
  ],
  "abstract": "We prove that any simply connected compact 3-Sasakian manifold, of dimension seven, is formal if and only if its second Betti number is $b_2<2$. In the opposite, we show an example of a 7-dimensional Sasaki-Einstein manifold, with second Betti number $b_2\\geq 2$, which is formal. Therefore, such an example does not admit any 3-Sasakian structure. Examples of 7-dimensional simply connected compact formal Sasakian manifolds, with $b_2\\geq 2$, are also given.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-11-28T21:11:09.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "53C25",
      "55S30",
      "55P62"
    ],
    "keywords": [
      "second betti number",
      "connected compact formal sasakian manifolds",
      "simply connected compact formal sasakian",
      "sasaki-einstein manifold",
      "dimension seven"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2015arXiv151108930F"
    }
  }
}