Non-existence of certain 3-structures

被引:5
作者
Kashiwada, T [1 ]
Cabrera, FM
Tripathi, MM
机构
[1] Saitama Coll, Dept Informat Sci, Kazo, Saitama 3470032, Japan
[2] Univ La Laguna, Dept Fundamental Math, Tenerife, Canary Isl, Spain
[3] Univ Lucknow, Dept Math & Astron, Lucknow 226007, Uttar Pradesh, India
[4] Pohang Univ Sci & Technol, Dept Math, Pohang 790784, South Korea
关键词
D O I
10.1216/rmjm/1181069625
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
We introduce the notion of an epsilon-framed 3-structure. This is a general structure which includes many widely studied 3-structures (almost quaternion, almost contact, hyper f-structure, almost product, etc.). We prove the existence of Riemannian metrics compatible with such a structure. We also study particular cases of epsilon-framed 3-structures showing the non-existence of certain remarkable types of such structures. First, we prove the non-existence of P-Sasakian almost r-paracontact 3-structures. Then, we show the nonexistence of almost r-contact S-3-structures (with r > 1). Finally, we establish the non-existence of proper trans-Sasakian almost contact 3-structures. A consequence of this last result is that any b-Kenmotsu almost contact 3-structure must be hypercosymplectic.
引用
收藏
页码:1953 / 1979
页数:27
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