{
  "annotation_id": "997ce114-eea5-4698-a85c-f6255fb3ae10",
  "date_created": "2026-03-02T18:02:47.510000Z",
  "date_modified": "2026-03-02T18:02:47.510000Z",
  "file_hash": "2c3e7455ec3a9836d74625ede7b80a25f6652fcfa775ca4e2d2ba8a80fd5f7b1",
  "private": false,
  "record": {
    "abstract": "The quantum dynamics of a free particle on a circle with point interaction is\ndescribed by a U(2) family of self-adjoint Hamiltonians. We provide a\nclassification of the family by introducing a number of subfamilies and thereby\nanalyze the spectral structure in detail. We find that the spectrum depends on\na subset of U(2) parameters rather than the entire U(2) needed for the\nHamiltonians, and that in particular there exists a subfamily in U(2) where the\nspectrum becomes parameter-independent. We also show that, in some specific\ncases, the WKB semiclassical approximation becomes exact (modulo phases) for\nthe system.",
    "arxiv_id": "quant-ph/9910062",
    "authors": [
      "Tamas Fulop",
      "Izumi Tsutsui"
    ],
    "categories": [
      "quant-ph",
      "math-ph",
      "math.MP"
    ],
    "doi": "10.1016/S0375-9601(99)00850-6",
    "title": "A Free Particle on a Circle with Point Interaction",
    "url": "https://arxiv.org/abs/quant-ph/9910062"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "f549dce8-645b-4683-8585-b3d6d730736f",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}