{
  "abstract": "The radius of a neutron star is closely related to the equation of state (EOS) of asymmetric nuclear matter, particularly to the nuclear symmetry energy. At fixed stellar mass, the neutron-star radius and the nuclear-matter pressure near saturation density approximately satisfy a pressure--radius (R-P) scaling relation, linking stellar geometry to strong-interaction matter. In the presence of dark matter (DM), changes in the stellar geometry can modify this relation. We investigate how GeV- and sub-GeV-scale DM affects the R-P relation in DM-admixed neutron stars (DANSs) within a gravity-only two-fluid framework. We extend the Buchdahl analytic solution to a two-fluid configuration to demonstrate this scaling and then use 21 nuclear EOSs to fit the relation $R_{\\rm NM}=\\bar C P_{\\rm NM}^η$ for $1M_\\odot$ and $1.4M_\\odot$ DANSs. The exponent $η$ and coefficient $\\bar C$ jointly quantify the DM-induced modification and depend on the DM particle mass, stellar DM content, and self-interaction strength. For bosonic DM, changes in $η$ and $\\bar C$ occur mainly in the sub-GeV range, whereas significant fermionic-DM effects persist up to about 1.5 GeV. Increasing the DM content or strengthening a repulsive self-interaction generally increases $η$ and decreases $\\bar C$. The modified R-P relation therefore encodes information about the DM particle mass, abundance, and self-interaction, and affect the extraction of the nuclear EOS from celestial observations. At DM masses of several hundred MeV, both fermionic and bosonic DM can also produce DM-dominated low-mass ($1M_\\odot$) DANSs with large radial extensions, for which the conventional scaling relation ceases to apply.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.06934",
  "author_total": 3,
  "authors": [
    {
      "name": "Zhi-yao Li"
    },
    {
      "name": "Wei-zhou Jiang"
    },
    {
      "name": "Dian Sun"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6zq9etv34d1yg.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.06934",
  "fulltext_url": null,
  "id": "6zq9etv34d1yg",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.06934",
  "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.SR"
    ],
    [
      "arxiv",
      "nucl-th"
    ],
    [
      "openalex",
      "3103|Pulsars and Gravitational Waves Research"
    ]
  ],
  "openalex": "W7221050654",
  "pdf_url": "https://arxiv.org/pdf/2610.06934",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-03",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/6zq9etv34d1yg.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:06Z",
      "native_id": "2610.06934",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.06934"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.SR",
      "subfield": "stellar"
    },
    {
      "field": "physics",
      "origin": "arxiv:nucl-th",
      "subfield": "nuclear"
    }
  ],
  "title": "Radii and Scaling Relations of Dark-Matter-Admixed Neutron Stars",
  "title_text": "Radii and Scaling Relations of Dark-Matter-Admixed Neutron Stars",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:06Z",
  "url": "https://research.draconitic.com/paper/6zq9etv34d1yg",
  "venue": "arXiv",
  "versions": []
}