{
  "annotation_id": "ce47e244-782e-46ed-bcf2-56f68c5491de",
  "date_created": "2026-03-02T18:00:50.252000Z",
  "date_modified": "2026-03-02T18:00:50.252000Z",
  "file_hash": "cd550141f55a03edc83f18a8c2fb48f834524ce3e40eadd3d211e2d5785d4ba9",
  "private": false,
  "record": {
    "abstract": "We report on a numerical observation of the train of zeptosecond pulses\nproduced by reflection of a relativistically intense femtosecond laser pulse\nfrom the oscillating boundary of an overdense plasma because of the Doppler\neffect. These pulses promise to become a unique experimental and technological\ntool since their length is of the order of the Bohr radius and the intensity is\nextremely high $\\propto 10^{19}$ W/cm$^2$. We present the physical mechanism,\nanalytical theory, and direct particle-in-cell simulations. We show that the\nharmonic spectrum is universal: the intensity of $n$th harmonic scales as\n$1/n^{p}$ for $n \u003c 4\\gamma^2$, where $\\gamma$ is the largest $\\gamma$--factor\nof the electron fluid boundary, $p=3$ and $p=5/2$ for the broadband and\nquasimonochromatic laser pulses respectively.",
    "arxiv_id": "physics/0405042",
    "authors": [
      "S. Gordienko",
      "A. Pukhov",
      "O. Shorokhov",
      "T. Baeva"
    ],
    "categories": [
      "physics.plasm-ph",
      "physics.gen-ph"
    ],
    "doi": "10.1103/PhysRevLett.93.115002",
    "title": "Relativistic Doppler effect: universal spectra and zeptosecond pulses",
    "url": "https://arxiv.org/abs/physics/0405042"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "6bbf7a21-23c5-46c2-9a16-5374a164ce9b",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}