{
  "annotation_id": "c5af6cdd-0e48-48a5-8677-1a71db596236",
  "date_created": "2026-03-02T18:01:00.603000Z",
  "date_modified": "2026-03-02T18:01:00.603000Z",
  "file_hash": "8a9e52eb42ce572ee5dabdaca1e0e1504d89fee3e8bb2c7e42325e4a9d72d0dd",
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  "record": {
    "abstract": "We present an accurate ab initio method of calculating isotope shifts and\nrelativistic shifts in atomic spectra. We test the method on neutral carbon and\nthree carbon ions. The relativistic shift of carbon lines may allow them to be\nincluded in analyses of quasar absorption spectra that seek to measure possible\nvariations in the fine structure constant, alpha, over the lifetime of the\nUniverse. Carbon isotope shifts can be used to measure isotope abundances in\ngas clouds: isotope abundances are potentially an important source of\nsystematic error in the alpha-variation studies. These abundances are also\nneeded to study nuclear reactions in stars and supernovae, and test models of\nchemical evolution of the Universe.",
    "arxiv_id": "physics/0509253",
    "authors": [
      "J. C. Berengut",
      "V. V. Flambaum",
      "M. G. Kozlov"
    ],
    "categories": [
      "physics.atom-ph",
      "astro-ph"
    ],
    "doi": "10.1103/PhysRevA.73.012504",
    "journal_ref": "Phys.Rev.A73:012504,2006",
    "title": "Calculation of isotope shifts and relativistic shifts in CI, CII, CIII   and CIV",
    "url": "https://arxiv.org/abs/physics/0509253"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "a0f83891-cba3-4d54-bb52-5753fc3cc46e",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}