Virtual retractions, conjugacy separability and omnipotence
نویسندگان
چکیده
منابع مشابه
Virtual retractions, conjugacy separability and omnipotence
We use wreath products to provide criteria for a group to be conjugacy separable or omnipotent. These criteria are in terms of virtual retractions onto cyclic subgroups. We give two applications: a straightforward topological proof of the theorem of Stebe that infiniteorder elements of Fuchsian groups (of the first type) are conjugacy distinguished, and a proof that surface groups are omnipotent.
متن کاملSubgroup separability and virtual retractions of groups
We begin by recalling that if Γ is a group, andH a subgroup of Γ, then Γ is calledH-separable if for every g ∈ Γ\H, there is a subgroup K of finite index in Γ such that H ⊂ K but g / ∈ K. The group Γ is called subgroup separable (or LERF) if Γ is H-separable for all finitely generated subgroups H. As is well-known LERF is a powerful property in the setting of low-dimensional topology which has ...
متن کاملSubgroup Separability and Conjugacy Separability of Certain HNN Extensions
In this note, we give characterizations for certain HNN extensions of polycyclic-by-finite groups with central associated subgroups to be subgroup separable and conjugacy separable. We shall do this by showing the equivalence of subgroup separability and conjugacy separability in this type of HNN extensions. 2000 Mathematics Subject Classification: Primary 20E06, 20E26; Secondary 20F10, 20F19
متن کاملConjugacy separability of certain torsion groups
It is shown that certain torsion groups studied by Grigorchuk and by Gupta and Sidki are conjugacy separable. 1. Introduction. In [1, 2, 3], R. I. Grigorchuk introduced and studied some remarkable new examples of finitely generated torsion groups. These groups are residually finite and amenable, and they fall into 20 isomorphism classes of p-groups for each prime p. Grigorchuk solved a problem ...
متن کاملOn Conjugacy Separability of Fibre Products
In this paper we study conjugacy separability of subdirect products of two free (or hyperbolic) groups. We establish necessary and sufficient criteria and apply them to fibre products to produce a finitely presented group G1 in which all finite index subgroups are conjugacy separable, but which has an index 2 overgroup that is not conjugacy separable. Conversely, we construct a finitely present...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Algebra
سال: 2010
ISSN: 0021-8693
DOI: 10.1016/j.jalgebra.2009.10.009