{
  "abstract": "We construct all axi-symmetric non-gradient m -quasi-Einstein structures on a two-sphere. This includes the spatial cross-section of the extreme Kerr black hole horizon corresponding to $$m=2$$ m = 2 , as well as a family of new regular metrics with $$m\\ne 2$$ m ≠ 2 given in terms of hypergeometric functions. We also show that in the case $$m=-1$$ m = - 1 with vanishing cosmological constant the only orientable compact solution in dimension two is the flat torus, which proves that there are no compact surfaces with a metrisable affine connection with skew Ricci tensor.",
  "abstract_shown": true,
  "affiliations": [
    "Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, CB3 0WA, Cambridge, UK",
    "Faculty of Physics, University of Warsaw, Pasteura 5, 02-093, Warsaw, Poland",
    "Department of Mathematics and Statistics and Department of Physics and Astronomy, McMaster University, Hamilton, L8S 4M1, Ontario, Canada",
    "School of Mathematics and Maxwell Institute for Mathematical Sciences, University of Edinburgh, King’s Buildings, EH9 3FD, Edinburgh, UK"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Alex Colling",
      "orcid": "0009-0009-2627-6519"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Maciej Dunajski",
      "orcid": "0000-0002-6477-8319"
    },
    {
      "affs": [
        2
      ],
      "name": "Hari K. Kunduri",
      "orcid": "0000-0001-6334-9478"
    },
    {
      "affs": [
        3
      ],
      "name": "James Lucietti",
      "orcid": "0000-0002-2371-9689"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/68n86xq34q77r.bib",
  "cited_by": 13,
  "doi": "10.1007/s12220-026-02459-0",
  "fulltext_url": null,
  "id": "68n86xq34q77r",
  "issns": [
    "1050-6926",
    "1559-002X"
  ],
  "landing_url": "https://doi.org/10.1007/s12220-026-02459-0",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2604|Geometric Analysis and Curvature Flows"
    ]
  ],
  "openalex": "W4392616777",
  "pdf_url": "https://link.springer.com/content/pdf/10.1007/s12220-026-02459-0.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-05-16",
  "publisher": "Springer Science+Business Media",
  "ris": "https://research.draconitic.com/paper/68n86xq34q77r.ris",
  "sources": [
    {
      "first_seen": "2026-11-04T13:21:00Z",
      "native_id": "W4392616777",
      "source": "openalex",
      "url": "https://doi.org/10.1007/s12220-026-02459-0"
    }
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  "subjects": [
    {
      "field": "mathematics",
      "origin": "openalex:2604|Geometric Analysis and Curvature Flows",
      "subfield": "general"
    }
  ],
  "title": "New Quasi-Einstein Metrics on a Two-Sphere",
  "title_text": "New Quasi-Einstein Metrics on a Two-Sphere",
  "type": "peer-reviewed",
  "updated_at": "2026-11-09T13:21:00Z",
  "url": "https://research.draconitic.com/paper/68n86xq34q77r",
  "venue": "Journal of Geometric Analysis",
  "versions": []
}