troponins
发表于 2025-3-30 10:15:15
Pregroups and Lyndon Length Functions, go back to Baer [.]. A pregroup is a set with a partial multiplication having certain group-like properties, to which one can associate a group (the universal group of the pregroup), and there is a normal form for the elements of the group in terms of the pregroup. This generalises the construction
tooth-decay
发表于 2025-3-30 13:17:29
,ℝ-Tree Actions are Not Determined by the Translation Lengths of Finitely Many Elements,nslation length functions on . which arise from (small) .-actions on ℝ-trees. It is well known that, for any finitely generated group ., an element of Hom(.(2, ℂ)) is determined up to conjugation in .(2,ℂ) by the traces of a finite set of elements of .. (See, for example, [.].) The purpose of this p
星球的光亮度
发表于 2025-3-30 16:44:13
The Boundary of Outer Space in Rank Two,ce has come to be known as “outer space.” Outer space can be defined as a space of free actions of .. on simplicial ℝ-trees; we require that all actions be minimal, and we identify two actions if they differ only by scaling the metric on the ℝ-tree. To describe the topology on outer space, we associ
Chipmunk
发表于 2025-3-31 00:04:14
,Cohomological dimension of groups acting on ℝ-trees,ch act freely on ℝ-trees. It is a classical theorem that any group which acts freely, without inversions, on a simplicial tree is free. If . is a Λ-tree for Λ ⊂ ℝ a subgroup (possibly equal to ℝ itself), it is clear that not only free groups can act freely on an ℝ-tree but that free abelian groups,