{
  "abstract": "In the minimal type-I seesaw, one right-handed neutrino (RHN) can decouple from neutrino mass generation. Such a state is usually neglected, yet its feeble couplings make it long-lived, and it can dominate the energy density of the Universe before decaying. We study this in a minimal $U(1)_{B-L}$ model, where the RHNs are produced through $B-L$ gauge interactions, for the cases of a decoupled lightest RHN $N_1$ and a decoupled heaviest RHN $N_3$. The resulting early matter-dominated era dilutes the baryon asymmetry, and for decoupled $N_3$ it also delays the equilibration of the charged-lepton Yukawa interactions, allowing a lighter $N_1$ to generate the asymmetry in the unflavoured regime. Breaking $U(1)_{B-L}$ forms cosmic strings whose gravitational-wave background acquires a spectral break from the early matter-dominated era, with a frequency set by the decoupled RHN mass and the lightest neutrino mass, within reach of future detectors such as SKA, THEIA, LISA, $μ$ARES, DECIGO and ET.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.18334",
  "author_total": 3,
  "authors": [
    {
      "name": "Stephen F. King"
    },
    {
      "name": "Rishav Roshan"
    },
    {
      "name": "Sudipta Show"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/821fhxqr00m0f.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.18334",
  "fulltext_url": null,
  "id": "821fhxqr00m0f",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.18334",
  "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|Particle physics theoretical and experimental studies"
    ]
  ],
  "openalex": "W7221801320",
  "pdf_url": "https://arxiv.org/pdf/2610.18334",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-13",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/821fhxqr00m0f.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:11Z",
      "native_id": "2610.18334",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.18334"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Cosmological Consequences of a Highly Decoupled Right-handed Neutrino",
  "title_text": "Cosmological Consequences of a Highly Decoupled Right-handed Neutrino",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:11Z",
  "url": "https://research.draconitic.com/paper/821fhxqr00m0f",
  "venue": "arXiv",
  "versions": []
}