{
  "annotation_id": "419690a2-4bc7-4ec9-872b-91f90c57cb19",
  "date_created": "2026-03-02T18:01:49.285000Z",
  "date_modified": "2026-03-02T18:01:49.285000Z",
  "file_hash": "a026ea28dab02f5d1e07b053f4f839b384846dcd949c10d02cdd530feeca8352",
  "private": false,
  "record": {
    "abstract": "The second central extension of the planar Galilei group has been alleged to\nhave its origin in the spin variable. This idea is explored here by considering\nlocal Galilean covariant field theory for free fields of arbitrary spin. It is\nshown that such systems generally display only a trivial realization of the\nsecond central extension. While it is possible to realize any desired value of\nthe extension parameter by suitable redefinition of the boost operator, such an\napproach has no necessary connection to the spin of the basic underlying field.",
    "arxiv_id": "quant-ph/0203109",
    "authors": [
      "C. R. Hagen"
    ],
    "categories": [
      "quant-ph",
      "hep-th"
    ],
    "doi": "10.1016/S0370-2693(02)02032-4",
    "journal_ref": "Phys.Lett. B539 (2002) 168-171",
    "title": "Second central extension in Galilean covariant field theory",
    "url": "https://arxiv.org/abs/quant-ph/0203109"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "5c11a8ce-7d56-4903-8d66-24536eec8119",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}