On Generalised Free Products of Conjugacy Separable Groups
نویسندگان
چکیده
In this paper we prove that a free product of conjugacy separable groups A and B, amalgamating a cyclic subgroup, is conjugacy separable if A and B are subgroup separable, cyclic conjugacy separable, 2-free, and residually p-finite, for all prime numbers p. The following result is an example of the applications we obtain as consequences of our main theorem. Let A and B each be a free product of surface groups, amalgamating a maximal cyclic subgroup. Then a free product of A and B, amalgamating a cyclic subgroup, is conjugacy separable. Q 1996
منابع مشابه
On 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 کاملFinite Index Subgroups of Conjugacy Separable Groups
We construct an example of conjugacy separable group possessing a not conjugacy separable subgroup of finite index. We give also a sufficient condition for a conjugacy separable group to preserve this property when passing to subgroups of finite index. We establish also conjugacy separability of finitely presented residually free groups using impressive results of Bridson and Wilton [BW-07].
متن کاملProfinite properties of graph manifolds
LetM be a closed, orientable, irreducible, geometrizable 3-manifold. We prove that the profinite topology on the fundamental group of π1(M) is efficient with respect to the JSJ decomposition of M . We go on to prove that π1(M) is good, in the sense of Serre, if all the pieces of the JSJ decomposition are. We also prove that if M is a graph manifold then π1(M) is conjugacy separable. A group G i...
متن کاملOn the Conjugacy Separability in the Class of Finite P -groups of Finitely Generated Nilpotent Groups
It is proved that for any prime p a finitely generated nilpotent group is conjugacy separable in the class of finite p-groups if and only if the tor-sion subgroup of it is a finite p-group and the quotient group by the torsion subgroup is abelian. 1. Let K be a class of groups. A group G is called residual K (or K-residual) if for each non-unit element a ∈ G there is a homomorphism ϕ of G onto ...
متن کاملThe Figure Eight Knot Group is Conjugacy Separable
We prove that torsion free subgroups of PGL2(C) (abstractly) commensurable with the Euclidean Bianchi groups are conjugacy separable. As a consequence we deduce the result stated in the title.
متن کامل