{
  "abstract": "The cosmic reheating is an important epoch in the very early Universe, and has significant impacts on the primordial black hole (PBH) abundance and the scalar-induced gravitational wave (SIGW) spectrum. The relevant energy scale and the constituents of cosmic medium are encoded in the reheating frequency $f_{\\mathrm{reh}}$ and the equation of state parameter $w$. In this work, we perform a full parameter space Bayesian inference, using the NANOGrav 15-yr dataset to constrain the thermal history of reheating. Treating $f_{\\mathrm{reh}}$ and $w$ as free parameters, we systematically investigate the Dirac $δ$, narrow and broad log-normal primordial power spectra. Current pulsar timing array data can effectively constrain the peak frequency of the SIGW spectrum as $f_{\\rm p}\\sim 10^{-7.6}$--$10^{-7.0}$ Hz, along with $f_{\\rm reh}\\sim 10^{-9.0}$--$10^{-8.3}$ Hz and $w\\sim 0.19$--$0.79$ (the $68\\%$ confidence level), when the power spectrum has a relatively narrow width $Δ\\lesssim 1$. A broader power spectrum introduces a smoothing effect that obscures the characteristic frequency knee in the SIGW spectrum, leading to the loss of information about cosmic reheating. Furthermore, for the Dirac $δ$ and narrow spectra, the PBH masses associated with the SIGWs are anchored at the planetary mass scale around $10^{-6}$--$10^{-4} M_{\\odot}$. This establishes a consistent physical framework that naturally bridges the nanohertz gravitational wave background with the dark matter candidates implied by the Optical Gravitational Lensing Experiment microlensing events.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "Journal reference: Phys. Rev. D 114, 083520 (2026)",
  "arxiv": "2610.18460",
  "author_total": 3,
  "authors": [
    {
      "name": "Qi-Lin Yang"
    },
    {
      "name": "Shi-Jie Wang"
    },
    {
      "name": "Nan Li"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/96m4yqt5db08f.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.18460",
  "fulltext_url": null,
  "id": "96m4yqt5db08f",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.18460",
  "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"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2610.18460",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-13",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/96m4yqt5db08f.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:11Z",
      "native_id": "2610.18460",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.18460"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    }
  ],
  "title": "Constraints on the cosmic reheating history from PTA data",
  "title_text": "Constraints on the cosmic reheating history from PTA data",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:11Z",
  "url": "https://research.draconitic.com/paper/96m4yqt5db08f",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1103/zpvp-rmd8",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}