{
  "abstract": "We show that horizon-scale magnetic fields around supermassive black holes (SMBHs), only limited by gravity, yield a universal, model-independent ceiling on electromagnetic energy density. For rotating SMBHs, this field enables particle acceleration up to $\\sim\\!10^{27}$\\,eV set solely by fundamental constants. We identify a parameter space in accretion rate and magnetic field strength in which quiescent nuclei simultaneously satisfy the transparency conditions for Ultra-High-Energy Cosmic Rays (UHECR) escape and the field requirements for reaching Ultra-High Energies (UHE), naturally complementing photon-rich Active Galactic Nuclei (AGN), which favor neutrino production but suppress UHECR escape. We observe that, when including curvature energy losses, the energy of the primaries scales weakly as $E_{\\rm curv}\\!\\propto\\!M^{1/4}$ and allows to achieve UHE across different compositions and SMBHs masses ($10^6$--$10^{10}\\,M_\\odot$), without requiring extreme spins or super-Eddington accretion. A cross-correlation of the Pierre Auger Observatory (PAO) public data with galaxies hosting reliably measured SMBH masses, separating AGN from quiescent hosts, reveals marginal local excesses ($\\lesssim\\!2.8σ$) consistent with isotropy after correcting for the look-elsewhere effect. The framework provides a direct link between black-hole physics and the maximum energies of cosmic particles, and defines concrete observational tests for next-generation UHECR datasets.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.23393",
  "author_total": 5,
  "authors": [
    {
      "name": "Elena Manao"
    },
    {
      "name": "Elisa Resconi"
    },
    {
      "name": "Frank M. Rieger"
    },
    {
      "name": "Paolo Padovani"
    },
    {
      "name": "Gia Dvali"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1xsackp88nkz1.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.23393",
  "fulltext_url": null,
  "id": "1xsackp88nkz1",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.23393",
  "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.GA"
    ],
    [
      "arxiv",
      "astro-ph.HE"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2610.23393",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-16",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/1xsackp88nkz1.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:30:32Z",
      "native_id": "2610.23393",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.23393"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "Exploring Cosmic Rays from Gravity-Limited Acceleration at Supermassive Black Holes",
  "title_text": "Exploring Cosmic Rays from Gravity-Limited Acceleration at Supermassive Black Holes",
  "type": "preprint",
  "updated_at": "2026-10-30T12:33:28Z",
  "url": "https://research.draconitic.com/paper/1xsackp88nkz1",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1103/8p34-jczv",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}