{
  "annotation_id": "c33faedd-ef44-4d4a-981f-03f6ec6276c8",
  "date_created": "2026-03-02T18:00:32.715000Z",
  "date_modified": "2026-03-02T18:00:32.715000Z",
  "file_hash": "562c494d9650c42def50f3b67f08d68f8e302a6047ba982cb00690f006cf196b",
  "private": false,
  "record": {
    "abstract": "We consider pulse propagation in a linear anomalously dispersive medium where\nthe group velocity exceeds the speed of light in vacuum (c) or even becomes\nnegative. A signal velocity is defined operationally based on the optical\nsignal-to-noise ratio, and is computed for cases appropriate to the recent\nexperiment where such a negative group velocity was observed. It is found that\nquantum fluctuations limit the signal velocity to values less than c.",
    "arxiv_id": "physics/0101068",
    "authors": [
      "A. Kuzmich",
      "A. Dogariu",
      "L. J. Wang",
      "P. W. Milonni",
      "R. Y. Chiao"
    ],
    "categories": [
      "physics.optics"
    ],
    "doi": "10.1103/PhysRevLett.86.3925",
    "title": "Signal velocity, causality, and quantum noise in superluminal light   pulse propagation",
    "url": "https://arxiv.org/abs/physics/0101068"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "b095fefc-823c-45e4-919e-a4058c279aa9",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}