{
  "abstract": "High-energy neutrinos from active galactic nuclei provide a powerful probe of dark matter (DM) spikes surrounding supermassive black holes. While elastic neutrino-DM scattering mediated by a light particle produces little net attenuation due to regeneration, inelastic scattering, $νχ_1\\toνχ_2$, introduces a nonzero minimum energy loss, $E_{\\rm th}$. We show that this threshold prevents the near-cancellation between attenuation and regeneration, producing a distinctive spectral deficit above $E_{\\rm th}$ accompanied by a pile-up below it. Solving the full neutrino cascade, including repeated scattering and secondary neutrinos from excited-state decays, we demonstrate that this feature persists for both narrow and broad energy-transfer kernels. Using public IceCube data for NGC 1068 and an unbinned likelihood analysis with a freely fitted intrinsic power-law spectrum, we derive upper limits on the asymptotic optical depth of $τ_0<26-39$ for a narrow kernel (kernel width $ε=0.01$) over $E_{\\rm th}=0.24-3.0$ TeV and $τ_0<20-26$ for a broad kernel ($ε=0.36$) over $E_{\\rm th}=0.24-2.4$ TeV, at the nominal $90\\%$ confidence level. An intrinsic high-energy cutoff weakens the narrow-kernel limits by factors of $2.2-7.4$ and the broad-kernel limits by factors of $2.0-5.0$. We further investigate DM velocity effects and combine NGC 1068 with CGCG 420-015 and TXS 0506+056 to extend the threshold reach. In a vector-mediator realization, an optimistic adiabatic DM spike can yield constraints on the neutrino coupling competitive with laboratory bounds for broad energy-transfer kernels.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.35620",
  "author_total": 2,
  "authors": [
    {
      "name": "Cheng-Wei Chiang"
    },
    {
      "name": "Van Que Tran"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ec7bjvhcaajby.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.35620",
  "fulltext_url": null,
  "id": "ec7bjvhcaajby",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.35620",
  "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",
      "hep-ph"
    ],
    [
      "openalex",
      "3106|Dark Matter and Cosmic Phenomena"
    ]
  ],
  "openalex": "W7223811573",
  "pdf_url": "https://arxiv.org/pdf/2610.35620",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-26",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ec7bjvhcaajby.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:35Z",
      "native_id": "2610.35620",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.35620"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Threshold effects of inelastic neutrino-dark-matter scattering in AGN spikes",
  "title_text": "Threshold effects of inelastic neutrino-dark-matter scattering in AGN spikes",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:35Z",
  "url": "https://research.draconitic.com/paper/ec7bjvhcaajby",
  "venue": "arXiv",
  "versions": []
}