QUASI-HOMOMORPHISMS ON MAPPING CLASS GROUPS
QUASI-HOMOMORPHISMS ON MAPPING CLASS GROUPS
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DOI：
10.3336/gm.42.1.15
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发表时间：
2007-02
影响因子：
0.4
通讯作者：
M. Bestvina;K. Fujiwara
中科院分区：
文献类型：
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作者：
M. Bestvina;K. Fujiwara
讨论了映射类群上拟同态的构造。我们知道存在无界准同态，这些无界准同态在限定于特定子群时是有界的，因此我们可以推导出映射类群不是由这些子群产生的有界的。在本文中，我们扩大了这类子群。推广的动机是考虑自由群的一阶理论。
We rene the construction of quasi-homomorphisms on mapping class groups. It is useful to know that there are unbounded quasi-homomorphisms which are bounded when restricted to particular subgroups since then one deduces that the mapping class group is not boundedly generated by these subgroups. In this note we enlarge the class of such subgroups. The generalization is motivated by considerations in rst order theory of free groups.