{
  "annotation_id": "87511709-be53-453d-b282-76d7dd3a148d",
  "date_created": "2026-03-02T18:00:46.687000Z",
  "date_modified": "2026-03-02T18:00:46.687000Z",
  "file_hash": "b2e1d2b0b7c5ba94d67ffa67ad38222197d958f990af714700a4f54d065b5cf7",
  "private": false,
  "record": {
    "abstract": "We present an ab initio method of calculation of isotope shift in atoms with\na few valence electrons, based on the configuration-interaction calculation of\nenergy. The main motivation for developing the method comes from the need to\nanalyze whether differences in isotope abundance in early universe can\ncontribute to the observed anomalies in quasar absorption spectra. The current\nbest explanation for these anomalies is the assumption that the fine structure\nconstant, alpha, was smaller at early epoch. We show that we can calculate the\nisotope shift in magnesium with good accuracy.",
    "arxiv_id": "physics/0312137",
    "authors": [
      "J. C. Berengut",
      "V. A. Dzuba",
      "V. V. Flambaum",
      "M. G. Kozlov"
    ],
    "categories": [
      "physics.atom-ph"
    ],
    "doi": "10.1103/PhysRevA.69.044102",
    "journal_ref": "Phys.Rev.A69:044102,2004",
    "title": "Configuration interaction calculation for the isotope shift in Mg I",
    "url": "https://arxiv.org/abs/physics/0312137"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "35b66dec-ad23-43be-befe-0ee144088009",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}