{
  "abstract": "We present a generalization of T-duality, called $T_2$-duality, that captures certain aspects of U-duality in M-theory. In particular, it features backgrounds that contain a 2-gerbe over a principal torus bundle, structures familiar from eleven-dimensional supergravity backgrounds. In special cases, it also incorporates S-duality in a precise sense. Our main result is a theorem characterizing $T_2$-dual pairs through spans of categorified principal bundles with connections, giving explicit rules for constructing a $T_2$-dual for a given background. A number of explicit examples illustrate how the various characteristic classes are mapped between the left and right backgrounds. For two-dimensional torus fibers, we also relate our construction to the combination of dimensional reduction and T-duality that links eleven-dimensional supergravity to type IIB supergravity. Finally, we discuss how $T_2$-duality arises from a Buscher-like span of 3d sigma models.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.12383",
  "author_total": 3,
  "authors": [
    {
      "name": "Gianni Gagliardo"
    },
    {
      "name": "Christian Saemann"
    },
    {
      "name": "Roberto Tellez-Dominguez"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/drv5g14w84d98.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.12383",
  "fulltext_url": null,
  "id": "drv5g14w84d98",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.12383",
  "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",
      "hep-th"
    ],
    [
      "arxiv",
      "math-ph"
    ],
    [
      "arxiv",
      "math.DG"
    ],
    [
      "arxiv",
      "math.MP"
    ],
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      "openalex",
      "3106|Black Holes and Theoretical Physics"
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  "openalex": "W7221126030",
  "pdf_url": "https://arxiv.org/pdf/2610.12383",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-08",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/drv5g14w84d98.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:54Z",
      "native_id": "2610.12383",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.12383"
    }
  ],
  "subjects": [
    {
      "field": "mathematics",
      "origin": "arxiv:math.DG",
      "subfield": "geometry-topology"
    },
    {
      "field": "mathematics",
      "origin": "arxiv:math-ph",
      "subfield": "mathematical-physics"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-th",
      "subfield": "high-energy"
    }
  ],
  "title": "Differential $T_2$-Duality and Spans of Principal 3-Bundles with Connections",
  "title_text": "Differential T_2-Duality and Spans of Principal 3-Bundles with Connections",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:58Z",
  "url": "https://research.draconitic.com/paper/drv5g14w84d98",
  "venue": "arXiv",
  "versions": []
}