AI 中文总结
本文证明迭代循环融合积中的群具有线性共轭长度,推广了已有结果,并推广至广义Baumslag-Solitar群及单关系群,为相关猜想提供证据。
AI 中文摘要
设 $\mathcal{A}_0$ 为某个可数字母表上有限生成自由群的集合,并归纳定义 $\mathcal{A}_r$ 为 $\mathcal{A}_{r-1}$ 与融合自由积 $G_1*_{\mathbb{Z}}G_2$ 的集合之并,其中 $G_1,G_2\in \mathcal{A}_{r-1}$。我们证明,对所有 $r$,$\mathcal{A}_r$ 中每个元素都具有线性共轭长度,这量化了 Larsen 的一个结果,并推广了 Kharlampovich 和 Myasnikov 的一个结果。这一结论是通过对自由群的一族迭代 HNN 扩张给出线性共轭长度界而实现的。此外,在附录中,我们改编了 A. Weiß 的一个证明,以表明所有广义 Baumslag-Solitar 群都具有线性共轭长度。作为推论,我们得到具有非平凡(的某个条件)的单关系群具有线性共轭长度,为 Bridson、Riley 和 Sale 的一个猜想提供了证据。
英文摘要
Let $\mathcal{A}_0$ be the set of finitely generated free groups on some countable alphabet and and define $\mathcal{A}_r$ inductively as the union of $\mathcal{A}_{r-1}$ with the set of amalgamated free products $G_1\ast_{\ZZ}G_2$, where $G_1,G_2\in \mathcal{A}_{r-1}$. We show, for all $r$, that every element of $\mathcal{A}_r$ has linear conjugator length, quantifying a result of Larsen and extending a result of Kharlampovich and Myasnikov. This is achieved by a linear conjugator length bound on a family of iterated HNN extensions of free groups. Also, in an appendix, we adapt a proof of A. Wei$ß$ to show that all Generalized Baumslag-Solitar Groups have linear conjugator length. As a consequence, we obtain that one-relator groups with non-trivial center have linear conjugator length, giving evidence for a conjecture of Bridson, Riley, and Sale.
CommentsIncludes appendix by author