{
  "id": "1407.7346",
  "version": "v2",
  "published": "2014-07-28T07:53:52.000Z",
  "updated": "2015-03-08T22:32:56.000Z",
  "title": "Isomorphism classes of association schemes induced by Hadamard matrices",
  "authors": [
    "Mitsugu Hirasaka",
    "Kijung Kim",
    "Hyonju Yu"
  ],
  "comment": "12 pages",
  "categories": [
    "math.CO"
  ],
  "abstract": "Every Hadamard matrix $H$ of order $n > 1$ induces a graph with $4n$ vertices, called the Hadamard graph $\\Gamma(H)$ of $H$. Since $\\Gamma(H)$ is a distance-regular graph with diameter $4$, it induces a $4$-class association scheme $(\\Omega, S)$ of order $4n$. In this article we deal with fission schemes of $(\\Omega, S)$ under certain conditions, and for such a fission scheme we estimate the number of isomorphism classes with the same intersection numbers as the fission scheme.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2014-07-28T07:53:52.000Z",
      "comment": "13 pages",
      "journal": null,
      "doi": null
    },
    {
      "version": "v2",
      "updated": "2015-03-08T22:32:56.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "association schemes",
      "isomorphism classes",
      "hadamard matrices",
      "fission scheme",
      "class association scheme"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2014arXiv1407.7346H"
    }
  }
}