勾高順,曹文勝
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勾高順,曹文勝
(五邑大學(xué) 數(shù)學(xué)與計(jì)算科學(xué)學(xué)院,廣東 江門 529020)
秩為1的非緊對(duì)稱空間分別有:實(shí)的、復(fù)的、四元數(shù)的雙曲空間和Cayley雙曲平面. 由于四元數(shù)乘法的不可交換性,四元素雙曲空間的研究相對(duì)較少. 近來,Kim、Parker和曹文勝教授等國內(nèi)外學(xué)者在四元數(shù)雙曲空間的性質(zhì)做出了研究[6-8].
證明 非負(fù)性和對(duì)稱性顯然成立. 因此只需證明三角不等式
成立.
我們發(fā)現(xiàn)如下等式:
利用此等式可得:
另外,給出Cygan球面的定義:
本節(jié)將給出主要結(jié)果以及其相關(guān)證明.
在證明定理1之前需要關(guān)注一條重要引理:
根據(jù)命題2結(jié)合(2)中的多個(gè)等式可得:
a)得證. 類似的,可如下證明b):
下面將對(duì)定理1給出證明:
[1] BEARDON N F. The geomettry of discrete groups [M]. New York: Springer-verlag, 1983.
[2] GOLDMAN W M. Complex hyperbolic geometry [M]. Oxford: Oxford University Press, 1999.
[3] MOSTOW G D. On a remarkable class of polyhedron in complex hyperbolic space [J]. Pacific Journal of Mathematics, 1980, 86(1): 171-276.
[4] PARKER J R. Notes on complex hyperbolic geometry [M]. Cambridge: Cambridge University Press, 2010.
[5] KAMIYA S. Generalized isometric spheres and fundamental domains for discrete subgroup of(1,;) [J]. Proceedings of the Japan Academy, Series A, Mathematical Sciences, 2003, 79(5): 105-109.
[6] CAO Wensheng, GONGOPADHYAY K. Algebraic characterization of the isometries in complex and quaternionic hyperbolic plane [J]. Geometriae Dedicata, 2012, 157: 23-39.
[7] CAO Wensheng, PARKER J R. Jorgensen's inequality and collars in-dimensional quaternionic hyperbolic space [J]. Quarterly J Math. 2011, 62: 523-543.
[8] KIM I, PARKER J R. Geometry of quaternionic hyperbolic manifolds [J]. Mathematical Proceedings of the Cambridge Philosophical Society, 2003, 135(2): 291-320.
[9] CHEN Xingshen, GREENBERY L. Hyperbolic spaces, contributions to analysis [M]. New York: Academic Press, 1974.
[責(zé)任編輯:韋 韜]
GOUGao-shun, CAOWen-sheng
(School of Mathematics and Computational Science, Wuyi University, Jiangmen 529020, China)
1006-7302(2013)04-0010-05
O151.21.
A
2013-06-08
勾高順(1987—),男,重慶酉陽人,在讀碩士生,研究方向?yàn)閺?fù)分析;曹文勝,教授,博士,碩士生導(dǎo)師,研究方向?yàn)閺?fù)分析.