Izvestiya: Mathematics ( IF 0.8 ) Pub Date : 2021-02-23 , DOI: 10.1070/im8970 Yu. A. Neretin 1, 2, 3, 4
We consider a tree all whose vertices have countable valency. Its boundary is the Baire space and the set of irrational numbers is identified with by continued fraction expansions. Removing edges from , we get a forest consisting of copies of . A spheromorphism (or hierarchomorphism) of is an isomorphism of two such subforests regarded as a transformation of or . We denote the group of all spheromorphisms by . We show that the correspondence sends the Thompson group realized by piecewise -transformations to a subgroup of . We construct some unitary representations of , show that the group of automorphisms is spherical in and describe the train (enveloping category) of .
中文翻译:
关于齐次非局部有限树的球态群
我们考虑一棵树,它的所有顶点都具有可数的价数。它的边界是贝尔空间,无理数集由连分数展开式标识。从 中去除边,我们得到一个由 的副本组成的森林。的球同构(或层级同构)是两个这样的子林的同构,被视为或的变换。我们用 表示所有球态的群。我们表明,对应将通过分段变换实现的 Thompson 群发送到 的子群。我们构造了 的一些酉表示,表明自同构群在并描述 的列车(包络类别)。