{
  "abstract": "We reformulate the lifting problem in the D1-D5 CFT as a supercharge cohomology problem, and enumerate BPS states according to the fortuitous/monotone classification. Working in the deformed T^4 T 4 symmetric orbifold theory, we give precise definitions of monotone and fortuitous cohomology classes generalizing the definitions in [C.-M. Chang and Y.-H. Lin, arXiv: 2402.10129] and illustrate them in the N=1 N = 1 theory. For N=2 N = 2 , we construct the cohomology explicitly and match it to the exact BPS partition function. We further describe how to assemble BPS states at smaller N N into BPS states at larger N N , and interpret their holographic duals as black hole bound states and massive stringy excitations on smooth horizonless (e.g. Lunin-Mathur) geometries.",
  "abstract_shown": true,
  "affiliations": [
    "Beijing Institute of Mathematical Sciences and Applications",
    "Tsinghua University",
    "Yau Mathematical Sciences Center",
    "Harvard University",
    "Texas A&M University",
    "University of Southern California"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 3,
  "authors": [
    {
      "affs": [
        0,
        1,
        2
      ],
      "name": "Chi-Ming Chang",
      "orcid": "0000-0002-8978-2613"
    },
    {
      "affs": [
        3
      ],
      "name": "Ying‐Hsuan Lin",
      "orcid": "0000-0001-8904-1287"
    },
    {
      "affs": [
        4,
        5
      ],
      "name": "Haoyu Zhang",
      "orcid": "0009-0008-4855-2329"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4mkdabv21s7wx.bib",
  "cited_by": 17,
  "doi": "10.21468/scipostphys.21.4.096",
  "fulltext_url": null,
  "id": "4mkdabv21s7wx",
  "issns": [
    "2542-4653"
  ],
  "landing_url": "https://scipost.org/10.21468/SciPostPhys.21.4.096",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3106|Black Holes and Theoretical Physics"
    ]
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  "openalex": "W4406273430",
  "pdf_url": "https://scipost.org/10.21468/SciPostPhys.21.4.096/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-19",
  "publisher": "Stichting SciPost",
  "ris": "https://research.draconitic.com/paper/4mkdabv21s7wx.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:57Z",
      "native_id": "10.21468/scipostphys.21.4.096",
      "source": "crossref",
      "url": "https://scipost.org/10.21468/SciPostPhys.21.4.096"
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    {
      "first_seen": "2026-11-04T13:21:01Z",
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      "url": "https://doi.org/10.21468/scipostphys.21.4.096"
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  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3106|Black Holes and Theoretical Physics",
      "subfield": "high-energy"
    }
  ],
  "title": "Fortuity in the D1-D5 system",
  "title_text": "Fortuity in the D1-D5 system",
  "type": "peer-reviewed",
  "updated_at": "2026-11-04T13:21:01Z",
  "url": "https://research.draconitic.com/paper/4mkdabv21s7wx",
  "venue": "SciPost Physics",
  "versions": []
}