{
  "abstract": "We propose a model in which the observed cosmic microwave background birefringence arises from the interaction of photons with a stiff ($w=1$) pseudo-scalar field that today contributes a subdominant fraction of the total energy density, distinct from both dark matter and dark energy. Big Bang Nucleosynthesis constrains the cosmological density of the stiff field, leading to a lower bound for its coupling with photons, $g_{ϕγ} > 8.9 \\times 10^{-14}\\,\\mathrm{GeV}^{-1}$. Photon conversion in cluster-hosted quasars sets an upper bound, $g_{ϕγ} < 5.0 \\times 10^{-13}\\,\\mathrm{GeV}^{-1}$. Therefore, there is a narrow window for the discovery of this cosmological component that can be explored in the forthcoming years with astrophysical axion searches. Moreover, we show that this scenario leads to gravitational-wave signals that can be tested with planned experiments.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.27082",
  "author_total": 6,
  "authors": [
    {
      "name": "Andrea Minotti"
    },
    {
      "name": "Yunzhi Wu"
    },
    {
      "name": "Tiziano Zanzarella"
    },
    {
      "name": "Nicolao Fornengo"
    },
    {
      "name": "Marco Regis"
    },
    {
      "name": "Marco Taoso"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/155jdjs3them0.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.27082",
  "fulltext_url": null,
  "id": "155jdjs3them0",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.27082",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.CO"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "openalex",
      "3106|Dark Matter and Cosmic Phenomena"
    ]
  ],
  "openalex": "W7223152327",
  "pdf_url": "https://arxiv.org/pdf/2610.27082",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-19",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/155jdjs3them0.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:04Z",
      "native_id": "2610.27082",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.27082"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Cosmic birefringence from a stiff axion field and its cosmological implications",
  "title_text": "Cosmic birefringence from a stiff axion field and its cosmological implications",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:04Z",
  "url": "https://research.draconitic.com/paper/155jdjs3them0",
  "venue": "arXiv",
  "versions": []
}