Abstract
An important problem in quaternionic hyperbolic geometry is to classify ordered m-tuples of pairwise distinct points in the closure of quaternionic hyperbolic n-space, \(\overline{\mathbf{H}_{\mathbb H}^n}\), up to congruence in the holomorphic isometry group \(\mathrm{PSp}(n,1)\) of \(\mathbf{H}_{\mathbb H}^n\). In this paper we concentrate on two cases: \(m=3\) in \(\overline{\mathbf{H}_{\mathbb H}^n}\) and \(m=4\) on \(\partial \mathbf{H}_{\mathbb H}^n\) for \(n\ge 2\). New geometric invariants and several distance formulas in quaternionic hyperbolic geometry are introduced and studied for this problem. The congruence classes are completely described by quaternionic Cartan’s angular invariants and the distances between some geometric objects for the first case. The moduli space is constructed for the second case.
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References
Apanasov, B.N., Kim, I.: Cartan angular invariant and deformations of rank 1 symmetric spaces. Sbornik Math. 198(2), 147–169 (2007)
Beardon, A.F.: The Geometry of Discrete Groups. Spring, New York (1983)
Bisi, C., Gentili, G.: Möbius transformations and the Poincare distance in the quaternionic setting. Indiana Univ. Math. J. 58, 2729–2764 (2009)
Brehm, U.: The shape invariant of triangles and trigonometry in two-point homogeneous spaces. Geom. Dedicata. 33, 59–76 (1990)
Cao, C., Waterman, P.L.: Conjugacy invariants of Möbius Groups. Quasiconformal Mappings and Analysis. Springer, New York (1998)
Cao, W.S., Parker, J.R.: Jørgensen’s inequalities and collars in n-dimensional quaternionic hyperbolic space. Q. J. Math. 62, 523–543 (2011)
Cartan, E.: Sur le groupe de la g\(\acute{e}\)om\(\acute{e}\)trie hypersph\(\acute{e}\)rique. Comment. Math. Helv. 4, 158–171 (1932)
Chen, S.S., Greenberg, L.: Hyperbolic Spaces, Contributions to Analysis. Academic Press, New York (1974)
Cunha, H., Gusevskii, N.: On the moduli space of quadruples of points in the boundary of complex hyperbolic space. Transform. Groups 15(2), 261–283 (2010)
Cunha, H., Gusevskii, N.: The moduli space of points in the boundary of complex hyperbolic space. J. Geom. Anal. 22, 1–11 (2012)
Falbel, E., Platis, I.D.: The \({\rm {PU}}(2,1)\) confguration space of four points in \(S^3\) and the cross-ratio variety. Math. Ann. 340(4), 935–962 (2008)
Falbel, E.: A spherical CR structure on the complement of the fgure eight knot with discrete holonomy. J. Difer. Geom. 79(1), 69–110 (2008)
Goldman, W.M.: Complex hyperbolic geometry. Oxford University Press, New York (1999)
Grossi, C.: PhD Thesis, Universidade Estadual de Campinas, (2006)
Kim, I., Parker, J.R.: Geometry of quaternionic hyperbolic manifolds. Math. Proc. Camb. Philos. Soc. 135, 291–320 (2003)
Korányi, A., Reimann, H.M.: The complex cross-ratio on the Heisenberg group. Enseign. Math. 33, 291–300 (1987)
Parker, J.R.: Complex hyperbolic Kleinian groups. Cambridge University Press (to appear)
Parker, J.R., Platis, I.D.: Complex hyperbolic Fenchel–Nielsen coordinates. Topology 47(2), 101–135 (2008)
Parker, J.R., Platis, I.D.: Global geometrical coordinates on Falbel’s cross-ratio variety. Can. Math. Bull. 52, 285–294 (2009)
Platis, I.D.: Cross-ratios and the Ptolemaean inequality in boundaries of symmetric spaces of rank 1. Geometr. Dedicata. 169, 187–208 (2014)
Acknowledgments
This work was supported by National Natural Science Foundation of China and Educational Commission of Guangdong Province. The authors would like to thank Prof. John R. Parker and the referee for their useful suggestions, which totally reshaped and enhanced this paper.
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Cao, W. Congruence classes of points in quaternionic hyperbolic space. Geom Dedicata 180, 203–228 (2016). https://doi.org/10.1007/s10711-015-0099-z
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DOI: https://doi.org/10.1007/s10711-015-0099-z
Keywords
- Quaternionic cross-ratio
- Quaternionic Cartan’s angular invariant
- Gram matrix
- Congruence class
- Moduli space