arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2009.10052math.GR
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$\mathsf{Out}(F_n)$的生成子群的McCool Whitehead型定理

A McCool Whitehead type theorem for finitely generated subgroups of $\mathsf{Out}(F_n)$

Mladen Bestvina, Mark Feighn, Michael Handel

摘要:

S. Gersten宣布了一种算法,该算法将$F_n$的生成子群的共轭类的两个有限序列$\vec K=(K_1,\dots, K_N)$和$\vec K'=(K_1',\dots, K_N')$作为输入,并输出:(1)$\mathsf{YES}$或$\mathsf{NO}$,这取决于是否存在元素$θ\in \mathsf{Out}(F_n)$,使得如果存在,则$θ(\vec K)=\vec K'$与一个这样的$θ$一起,以及(2)固定$\vec K$的$\mathsf{Out}(F_n)$的子群的有限表示。S. Kalajdžievski发表了对该算法的验证。我们从Culler-Vogtmann的外层空间的角度提出了一种不同的算法。新的结果包括,分组的$\mathsf{Out}(F_n)$固定$\vec K$是类型$\mathsf{VF}$,这些结果的等变版本,应用程序,和统一的方法来解决这些问题。

英文摘要:

S. Gersten announced an algorithm that takes as input two finite sequences $\vec K=(K_1,\dots, K_N)$ and $\vec K'=(K_1',\dots, K_N')$ of conjugacy classes of finitely generated subgroups of $F_n$ and outputs: (1) $\mathsf{YES}$ or $\mathsf{NO}$ depending on whether or not there is an element $θ\in \mathsf{Out}(F_n)$ such that $θ(\vec K)=\vec K'$ together with one such $θ$ if it exists and (2) a finite presentation for the subgroup of $\mathsf{Out}(F_n)$ fixing $\vec K$. S. Kalajdžievski published a verification of this algorithm. We present a different algorithm from the point of view of Culler-Vogtmann's Outer space. New results include that the subgroup of $\mathsf{Out}(F_n)$ fixing $\vec K$ is of type $\mathsf{VF}$, an equivariant version of these results, an application, and a unified approach to such questions.

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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