{
  "abstract": "Testing the horizon properties of astrophysical black holes is a central goal of gravitational-wave astronomy. The recently identified Direct Wave (DW), a prompt non-quasinormal component of GW250114, provides a new probe of near-horizon physics. While it remains unclear whether the DW itself carries horizon information, we show that it enables a novel null test of horizon reflectivity. If the remnant is an exotic compact object (ECO) with a partially reflecting surface, inward plunge radiation is reflected and leaks back through the gravitational potential barrier, producing a delayed DW echo whose amplitude is set by the surface reflectivity ($|\\mathcal{R}_s|$). We construct the corresponding echo template, normalized by the observed DW, and search for it in quasinormal-mode-filtered data. We find no evidence for an echo ($\\ln\\mathcal{B}=-2.9$) and obtain the 90\\% credible bound $|\\mathcal{R}_s|<0.06$, corresponding to a reflected energy fraction below $0.4\\%$, for surfaces from $0.1\\, M_f$ to a Planck length from the would-be horizon. Our method thus turns the prompt ringdown signal into a direct test of horizon reflectivity.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.12429",
  "author_total": 3,
  "authors": [
    {
      "name": "R. Prasad"
    },
    {
      "name": "Subhodeep Sarkar"
    },
    {
      "name": "Sudipta Sarkar"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5wgh1xwey5674.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.12429",
  "fulltext_url": null,
  "id": "5wgh1xwey5674",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.12429",
  "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.HE"
    ],
    [
      "arxiv",
      "gr-qc"
    ],
    [
      "openalex",
      "3103|Pulsars and Gravitational Waves Research"
    ]
  ],
  "openalex": "W7221108961",
  "pdf_url": "https://arxiv.org/pdf/2610.12429",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-08",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5wgh1xwey5674.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:54Z",
      "native_id": "2610.12429",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.12429"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    },
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "Listening to the Horizon: Probing Near-Horizon Reflectivity with GW250114",
  "title_text": "Listening to the Horizon: Probing Near-Horizon Reflectivity with GW250114",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:54Z",
  "url": "https://research.draconitic.com/paper/5wgh1xwey5674",
  "venue": "arXiv",
  "versions": []
}