{
  "abstract": "We compute the entanglement entropy of quantum matter in spacetimes with a Killing horizon entirely on-shell, by integrating the first law of thermodynamics along a one-parameter family of equilibrium backgrounds labelled by the Hawking temperature. This yields a closed expression in terms of the renormalized stress-energy tensor and the Killing vector, finite by construction, with no replicas and no conical singularities. Its covariant form agrees with the matter terms of the Bardeen--Carter--Hawking mass variation formula. We show in details that for static patch of de Sitter space and for the non-rotating BTZ black hole it reproduces the conical entropy exactly, contact term $Q$ included.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.11777",
  "author_total": 2,
  "authors": [
    {
      "name": "D. V. Diakonov"
    },
    {
      "name": "Gleb S. Zverev"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4h8hqkvq1caxt.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.11777",
  "fulltext_url": null,
  "id": "4h8hqkvq1caxt",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.11777",
  "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-th"
    ],
    [
      "openalex",
      "3106|Black Holes and Theoretical Physics"
    ]
  ],
  "openalex": "W7221169722",
  "pdf_url": "https://arxiv.org/pdf/2610.11777",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-08",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4h8hqkvq1caxt.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:54Z",
      "native_id": "2610.11777",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.11777"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-th",
      "subfield": "high-energy"
    }
  ],
  "title": "Entanglement entropy of black holes from the first law of thermodynamics",
  "title_text": "Entanglement entropy of black holes from the first law of thermodynamics",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:54Z",
  "url": "https://research.draconitic.com/paper/4h8hqkvq1caxt",
  "venue": "arXiv",
  "versions": []
}