{
  "abstract": "The age of the cosmic neutrino is upon us. Aside from their fundamental importance to particle physics and the recent tensions in their mass scale $M_ν= \\sum m_ν$, neutrinos' degeneracies with other cosmological parameters in analyses of scale-dependent cosmic clustering will significantly affect the estimates of these parameters, making accurate, inexpensive, easily-implemented approximations essential tools for theoretical cosmology. We present a new linear approximation, SE-EdS, applicable to non-relativistic neutrinos and other hot dark matter, which is exact in the linear Einstein-de Sitter case, and < 3% accurate for a broad range of flat and non-flat cosmologies characterized by parameters $0.2 \\leq Ω_{m,0} \\leq 1$, $0 \\leq Ω_{ν,0} \\leq 0.018$, $-0.1 \\leq Ω_{K,0} \\leq 0.1$, and $w_0 \\leq -0.6$, at all length scales. This broad coverage in $Ω_{m,0}$ makes SE-EdS ideal for N-body simulations, whose redshift range $z \\lesssim 100$ demands accuracy for time-dependent $Ω_m$ between unity and the preferred late-time values $\\sim 0.3$. SE-EdS may be used to paint neutrinos into simulations in Fourier space, where its < 3% error and neutrinos' $\\leq$ 3% matter fraction guarantees < 0.1% errors in the total matter density contrast, thereby including neutrino effects upon clustering at negligible computational cost. We quantify the approximation's accuracy; extend it to a broad range of cosmologies; and explore its correspondence with higher-order corrections to existing linear response schemes. A simple implementation is available online at https://codeberg.org/upadhye/SE-EdS .",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.06399",
  "author_total": 2,
  "authors": [
    {
      "name": "Amol Upadhye"
    },
    {
      "name": "Yvonne Y. Y. Wong"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dzvnj83jthc2f.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.06399",
  "fulltext_url": null,
  "id": "dzvnj83jthc2f",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.06399",
  "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": null,
  "pdf_url": "https://arxiv.org/pdf/2611.06399",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/dzvnj83jthc2f.ris",
  "sources": [
    {
      "first_seen": "2026-11-05T15:20:56Z",
      "native_id": "2611.06399",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.06399"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Planting neutrino SE-EdS: A < 3% accurate clustering approximation for neutrinos and other hot dark matter",
  "title_text": "Planting neutrino SE-EdS: A < 3% accurate clustering approximation for neutrinos and other hot dark matter",
  "type": "preprint",
  "updated_at": "2026-11-06T18:21:10Z",
  "url": "https://research.draconitic.com/paper/dzvnj83jthc2f",
  "venue": "arXiv",
  "versions": []
}