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arXiv 2004.09905math.GR
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奇Coxeter群的自同构

Automorphisms of odd Coxeter groups

Tushar Kanta Naik, Mahender Singh

摘要:

奇Coxeter群$W$是一个允许所有指数$m_{ij}$为奇数或无穷大的Coxeter系统$(W,S)$的Coxeter群。本文研究了奇Coxeter群族,其相联标号图$\mathcal{V}_{(W,S)}$是树.已知这个族中的两个Coxeter群是同构的当且仅当它们允许具有相同秩和相同有限指数的多集的Coxeter系统。特别地,在这个家庭中的每个组是同构的一个组,承认一个Coxeter系统,其相关的标号图是一个星形树。给出了这类群的自同构群的完整刻画,并给出了自同构群分裂为内外自同构群的半直积的一个充分条件。作为应用,我们证明了这类Coxeter群满足$R_\infty$ -性质,并且是(余)-Hopfian群.对一类有限指数仅为3的奇Coxeter群的结构性质、自同构群、$\R_\infty$ -性质和(co)-Hopfi性质与辫子群和孪生群进行了比较.

英文摘要:

An odd Coxeter group $W$ is one which admits a Coxeter system $(W,S)$ for which all the exponents $m_{ij}$ are either odd or infinity. The paper investigates the family of odd Coxeter groups whose associated labeled graphs $\mathcal{V}_{(W,S)}$ are trees. It is known that two Coxeter groups in this family are isomorphic if and only if they admit Coxeter systems having the same rank and the same multiset of finite exponents. In particular, each group in this family is isomorphic to a group that admits a Coxeter system whose associated labeled graph is a star shaped tree. We give the complete description of the automorphism group of this group, and derive a sufficient condition for the splitting of the automorphism group as a semi-direct product of the inner and the outer automorphism groups. As applications, we prove that Coxeter groups in this family satisfy the $R_\infty$-property and are (co)-Hopfian. We compare structural properties, automorphism groups, $\R_\infty$-property and (co)-Hopfianity of a special odd Coxeter group whose only finite exponent is three with the braid group and the twin group.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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