{
  "id": "2102.11257",
  "version": "v1",
  "published": "2021-02-22T18:41:02.000Z",
  "updated": "2021-02-22T18:41:02.000Z",
  "title": "Axi-Higgs Cosmology",
  "authors": [
    "Leo WH Fung",
    "Lingfeng Li",
    "Tao Liu",
    "Hoang Nhan Luu",
    "Yu-Cheng Qiu",
    "S. -H. Henry Tye"
  ],
  "comment": "48 pages, 9 figures, comments welcome",
  "categories": [
    "hep-ph",
    "astro-ph.CO",
    "hep-th"
  ],
  "abstract": "If the Higgs vacuum expectation value $v$ in early universe is $\\sim 1 \\%$ higher than its present value $v_0=246$ GeV, the $^7$Li puzzle in BBN and the CMB/$\\Lambda$CDM tension with late-universe measurements on Hubble parameter are mitigated. We propose a model of an axion coupled to the Higgs field, named \"axi-Higgs\", with its mass $m_a \\sim 10^{-30} - 10^{-29}\\,{\\rm eV}$ and decay constant $f_a \\sim 10^{17} - 10^{18}\\,{\\rm GeV}$, to achieve this goal. The axion initial value $a_{\\rm ini}$ yields an initial $\\Delta v_{\\rm ini}/v_0 \\sim 0.01$ throughout the BBN-recombination epoch and a percent level contribution to the total matter density today. Because of its very large de Broglie wavelength, this axion matter density $\\omega_a$ suppresses the matter power spectrum, alleviating the CMB/$\\Lambda$CDM $S_8/\\sigma_8$ tension with the weak-lensing data. It also explains the recently reported isotropic cosmic birefringence by its coupling with photons. Adding the axion ($m \\sim 10^{-22}\\,$eV) in the fuzzy dark matter model to the axi-Higgs model allows bigger $\\Delta v_{\\rm rec}$ and $\\omega_a$ to address the Hubble and $S_8/\\sigma_8$ tensions simultaneously. The model predicts that $\\Delta v$ may be detected by the spectral measurements of quasars, while its oscillation may be observed in the atomic clock measurements.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-02-22T18:41:02.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "axi-higgs cosmology",
      "higgs vacuum expectation value",
      "fuzzy dark matter model",
      "total matter density today",
      "reported isotropic cosmic birefringence"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 48,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}