{
  "annotation_id": "f676dbce-4112-4b08-8524-6ccc096f02e0",
  "date_created": "2026-03-02T18:01:07.073000Z",
  "date_modified": "2026-03-02T18:01:07.073000Z",
  "file_hash": "bd3d9a906b5e6cc705b46b16fa3f1481a39bc074c71f370d581dd9a53a63ee18",
  "private": false,
  "record": {
    "abstract": "Superluminal behavior has been extensively studied in recent years,\nespecially with regard to the topic of superluminality in the propagation of a\nsignal. Particular interest has been devoted to Bessel-X waves propagation,\nsince some experimental results showed that these waves have both phase and\ngroup velocities greater that light velocity c. However, because of the lack of\nan exact definition of signal velocity, no definite answer about the signal\npropagation (or velocity of information) has been found. The present paper is a\nshort note that deals in a general way with this vexed question. By analyzing\nthe field of existence of the Bessel X-wave in pseudo-Euclidean space-time, it\nis possible to give a general description of the propagation, and to overcome\nthe specific question related to a definition of signal velocity.",
    "arxiv_id": "physics/0603104",
    "authors": [
      "D. Mugnai"
    ],
    "categories": [
      "physics.optics"
    ],
    "title": "Bessel-X waves: superluminal propagation and the Minkowski space-time",
    "url": "https://arxiv.org/abs/physics/0603104"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "2286ea35-fb2a-43b2-80d1-44e030dfb90c",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}