{
  "aliases": null,
  "backlinks": [
    {
      "field": "uses",
      "target": "78R2TV41D4"
    },
    {
      "field": "uses",
      "target": "AADNYSB6TC"
    },
    {
      "field": "uses",
      "target": "T1KR4KPX8P"
    },
    {
      "field": "defines",
      "target": "JY5TC2XCKH"
    }
  ],
  "body": "\n## Summary\n\nA group action is $k$-transitive when one group element can move any $k$ distinct points onto any other $k$ distinct points, in order.\nFor $k = 1$ this is a [[transitive action|02GK6HZYBT]], and larger $k$ means a stronger kind of symmetry.\nThe symmetric group $S_n$ is $n$-transitive and the alternating group $A_n$ is $(n-2)$-transitive on $n$ points, and a $2$-transitive group is always [[primitive|Y10S0751KG]].\nApart from symmetric and alternating groups, finite multiply transitive groups are rare: the [[Mathieu groups|T1KR4KPX8P]] are famous examples.\n\n## Explanations\n\n### L1 human\n\nA group acting on a set is $2$-transitive if, for any two ordered pairs of different points, some element sends the first pair to the second.\nThink of a set of seats and a group of allowed ways to reseat people.\nIf the group is $2$-transitive, any two people can be moved into any two chosen seats.\nAll permutations of $n$ points form an $n$-transitive group.\nThe rotations and reflections of a square act transitively on its four corners, but not $2$-transitively: two neighbouring corners cannot be moved onto two opposite corners.\n",
  "commit": "547b6eddb8f2feb8d579f2d633d22a27b7e132fc",
  "front": {
    "kind": "concept",
    "msc": [
      "20B20",
      "20B22"
    ],
    "name": "Multiply transitive group action",
    "same_as": {
      "wikidata": "Q4596974",
      "wikipedia": "Multiply transitive group action"
    },
    "sources": [
      {
        "url": "https://en.wikipedia.org/wiki/Multiply_transitive_group_action"
      }
    ],
    "specializes": [
      "02GK6HZYBT"
    ],
    "tag": "BDJ1AX4XBB"
  },
  "kind": "concept",
  "link": "https://math2.tamnd.com/node/BDJ1AX4XBB/",
  "links": [
    {
      "field": "specializes",
      "target": "02GK6HZYBT"
    }
  ],
  "markdown": "https://math2.tamnd.com/node/BDJ1AX4XBB.md",
  "msc": [
    "20B20",
    "20B22"
  ],
  "name": "Multiply transitive group action",
  "prov": null,
  "role": "",
  "source": "https://github.com/tamnd/math2/blob/main/nodes/BDJ/BDJ1AX4XBB.md",
  "status": null,
  "tag": "BDJ1AX4XBB",
  "uri": "m2://BDJ1AX4XBB",
  "url": "https://math2.tamnd.com/wiki/multiply-transitive-group-action/",
  "writing": {
    "tag": "BDJ1AX4XBB",
    "kind": "concept",
    "level": "W0",
    "next": [
      {
        "what": "an inventory row",
        "note": "the row of the inventory that the node accounts for",
        "have": 0,
        "want": 1
      },
      {
        "what": "a source with a locator",
        "have": 0,
        "want": 1
      }
    ]
  }
}
