Quasi-morphisms on the group of area-preserving diffeomorphisms of the 2-disk
Quasi-morphisms on the group of area-preserving diffeomorphisms of the 2-disk
复制标题
2-圆盘保面积微分同胚群的拟同态
DOI：
10.1090/s2330-1511-2014-00002-x
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Tomohiko Ishida
中科院分区：
文献类型：
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作者：
Tomohiko Ishida
最近Gambaudo和Ghys证明了2-圆盘D^2 $的保面积仿射群${\rm Diff}_\Omega^\infty（D^2，\partial D^2）$上存在无穷多个拟态射。为了证明，他们构造了从辫子群上的拟态射空间到${\rm Diff}_\Omega^\infty（D^2，\partial D^2）$上的拟态射空间的同态。本文研究了同态，证明了它的内射性。
Recently Gambaudo and Ghys proved that there exist infinitely many quasi-morphisms on the group ${\rm Diff}_\Omega^\infty (D^2, \partial D^2)$ of area-preserving diffeomorphisms of the 2-disk $D^2$. For the proof, they constructed a homomorphism from the space of quasi-morphisms on the braid group to the space of quasi-morphisms on ${\rm Diff}_\Omega^\infty (D^2, \partial D^2)$. In this paper, we study the homomorphism and prove its injectivity.