{
  "id": "0910.0742",
  "version": "v3",
  "published": "2009-10-05T12:48:14.000Z",
  "updated": "2009-12-30T15:48:50.000Z",
  "title": "Constraining the time variation of the coupling constants from cosmic microwave background: effect of Λ_{QCD}",
  "authors": [
    "Masahiro Nakashima",
    "Kazuhide Ichikawa",
    "Ryo Nagata",
    "Jun'ichi Yokoyama"
  ],
  "comment": "25 pages, 4 figures; references added",
  "categories": [
    "astro-ph.CO"
  ],
  "abstract": "We investigate constraints on the time variation of the fine structure constant between the recombination epoch and the present epoch, \\Delta\\alpha/\\alpha \\equiv (\\alpha_{rec} - \\alpha_{now})/\\alpha_{now}, from cosmic microwave background (CMB) taking into account simultaneous variation of other physical constants, namely the electron mass m_{e} and the proton mass m_{p}. In other words, we consider the variation of Yukawa coupling and the QCD scale \\Lambda_{QCD} in addition to the electromagnetic coupling. We clarify which parameters can be determined from CMB temperature anisotropy in terms of singular value decomposition. Assuming a relation among variations of coupling constants governed by a single scalar field (the dilaton), the 95% confidence level (C.L.) constraint on \\Delta\\alpha/\\alpha is found to be -8.28 \\times 10^{-3} < \\Delta\\alpha/\\alpha < 1.81 \\times 10^{-3}, which is tighter than the one obtained by considering only the change of \\alpha and m_{e}. We also obtain the constraint on the time variation of the proton-to-electron mass ratio \\mu \\equiv m_{p}/m_{e} to be -0.52 < \\Delta\\mu/\\mu < 0.17 (95% C.L.) under the same assumption. Finally, we also implement a forecast for constraints from the PLANCK survey.",
  "revisions": [
    {
      "version": "v3",
      "updated": "2009-12-30T15:48:50.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "cosmic microwave background",
      "time variation",
      "coupling constants",
      "constraint",
      "proton-to-electron mass ratio"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/1475-7516/2010/01/030",
      "journal": "Journal of Cosmology and Astro-Particle Physics",
      "year": 2010,
      "month": "Jan",
      "volume": 2010,
      "number": 1,
      "pages": "030"
    },
    "note": {
      "typesetting": "TeX",
      "pages": 25,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 832998,
      "adsabs": "2010JCAP...01..030N"
    }
  }
}