{
  "id": "1502.02739",
  "version": "v1",
  "published": "2015-02-09T23:51:24.000Z",
  "updated": "2015-02-09T23:51:24.000Z",
  "title": "Explicit construction of Ramanujan bigraphs",
  "authors": [
    "Cristina Ballantine",
    "Brooke Feigon",
    "Radhika Ganapathy",
    "Janne Kool",
    "Kathrin Maurischat",
    "Amy Wooding"
  ],
  "comment": "10 pages",
  "categories": [
    "math.NT"
  ],
  "abstract": "We construct explicitly an infinite family of Ramanujan graphs which are bipartite and biregular. Our construction starts with the Bruhat-Tits building of an inner form of $SU_3(\\mathbb Q_p)$. To make the graphs finite, we take successive quotients by infinitely many discrete co-compact subgroups of decreasing size.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-02-09T23:51:24.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "11E39",
      "11E57",
      "16W10"
    ],
    "keywords": [
      "ramanujan bigraphs",
      "explicit construction",
      "discrete co-compact subgroups",
      "ramanujan graphs",
      "inner form"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}