{
  "abstract": "Recent pulsar timing array (PTA) observations have reported evidence for a common low frequency signal consistent with a stochastic gravitational wave background. In this work, we investigate the cosmic string interpretation of this signal in a non-standard cosmological history between big bang nucleosynthesis and recombination, featuring an early matter-dominated era followed by a kination phase. Previous studies have shown that kination can significantly modify the cosmic-string-induced gravitational wave spectrum, generating characteristic features in the nanohertz range and producing a shape consistent with current PTA data. Building on this, we perform separate Bayesian analyses of the NANOGrav 15-year and EPTA DR2 New+ datasets to quantify the extent to which such a cosmological history is favored by the data. We find substantial evidence for a transient period of matter and kination domination over the standard cosmological history within a cosmic-string interpretation of the gravitational-wave signal, with a Bayes factor $3.63^{+0.22}_{-0.21}$ from the NANOGrav 15-year dataset, while leaving the inferred cosmic-string tension nearly unchanged. This cosmic-string-dominated scenario is particularly relevant if the contribution from supermassive black hole binaries (SMBHBs) is small, as hinted at by astrophysical population simulations. Compared with a scenario where gravitational waves are produced purely by SMBHBs, cosmic-string interpretations with and without an additional contribution from SMBHBs, across both expansion histories and datasets, reveal no significant preference.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.10674",
  "author_total": 3,
  "authors": [
    {
      "name": "Raymond T. Co"
    },
    {
      "name": "Siu Cheung Lam"
    },
    {
      "name": "Taegyu Lee"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2m0mxh7x7fgg3.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.10674",
  "fulltext_url": null,
  "id": "2m0mxh7x7fgg3",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.10674",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.CO"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "openalex",
      "3103|Pulsars and Gravitational Waves Research"
    ]
  ],
  "openalex": "W7221101398",
  "pdf_url": "https://arxiv.org/pdf/2610.10674",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-07",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/2m0mxh7x7fgg3.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:54Z",
      "native_id": "2610.10674",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.10674"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Interpretation of Nanohertz Gravitational Waves via Cosmic Strings in Post-BBN Matter and Kination Domination",
  "title_text": "Interpretation of Nanohertz Gravitational Waves via Cosmic Strings in Post-BBN Matter and Kination Domination",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:54Z",
  "url": "https://research.draconitic.com/paper/2m0mxh7x7fgg3",
  "venue": "arXiv",
  "versions": []
}