Peer-reviewedCC BYJournal of Geometric Analysis
New Quasi-Einstein Metrics on a Two-Sphere
4 affiliations
- 1Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, CB3 0WA, Cambridge, UK
- 2Faculty of Physics, University of Warsaw, Pasteura 5, 02-093, Warsaw, Poland
- 3Department of Mathematics and Statistics and Department of Physics and Astronomy, McMaster University, Hamilton, L8S 4M1, Ontario, Canada
- 4School of Mathematics and Maxwell Institute for Mathematical Sciences, University of Edinburgh, King’s Buildings, EH9 3FD, Edinburgh, UK
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≠ 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.
Related
BibTeX
@article{colling2026quasieinstein,
title = {{New Quasi-Einstein Metrics on a Two-Sphere}},
author = {Alex Colling and Maciej Dunajski and Hari K. Kunduri and James Lucietti},
journal = {Journal of Geometric Analysis},
year = {2026},
month = may,
doi = {10.1007/s12220-026-02459-0},
url = {https://doi.org/10.1007/s12220-026-02459-0},
note = {CC BY},
}
RIS
TY - JOUR
TI - New Quasi-Einstein Metrics on a Two-Sphere
AU - Alex Colling
AU - Maciej Dunajski
AU - Hari K. Kunduri
AU - James Lucietti
PY - 2026
DA - 2026/05/16
JO - Journal of Geometric Analysis
DO - 10.1007/s12220-026-02459-0
UR - https://doi.org/10.1007/s12220-026-02459-0
AB - 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≠ 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.
SN - 1050-6926
SN - 1559-002X
ER -