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北美退伍军人节(Veterans Day),12 日无更新
arXiv 1610.08545math.GR
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自由群的自同构群的拓扑与几何

The topology and geometry of automorphism groups of free groups

Karen Vogtmann

摘要:

在20世纪70年代Stallings表明,人们可以学到很多关于自由群和他们的自同构查看自由群作为基本群的图形和建模其自同构的同伦等价的图形。利用图来研究自由群的自同构群的进一步动力来自于图空间的引入,现在称为外层空间,$Out(F_n)$群在其中表现得很好。对外层空间及其$Out(F_n)$作用的研究继续提供关于$Out(F_n)$结构的新信息,但也发现了与许多其他群体、空间和看似无关的主题的惊人联系,从系统发育树到循环运算和模形式。在这次演讲中,我将重点介绍这些想法目前正在发展的各种方式。

英文摘要:

In the 1970s Stallings showed that one could learn a great deal about free groups and their automorphisms by viewing the free groups as fundamental groups of graphs and modeling their automorphisms as homotopy equivalences of graphs. Further impetus for using graphs to study automorphism groups of free groups came from the introduction of a space of graphs, now known as Outer space, on which the group $Out(F_n)$ acts nicely. The study of Outer space and its $Out(F_n)$ action continues to give new information about the structure of $Out(F_n)$, but has also found surprising connections to many other groups, spaces and seemingly unrelated topics, from phylogenetic trees to cyclic operads and modular forms. In this talk I will highlight various ways these ideas are currently evolving.

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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