Profinite completions of some groups acting on trees
Abstract
Description
We investigate the profinite completions of a certain family of groups acting on trees. It turns out that for some of the groups considered, the completions coincide with the closures of the groups in the full group of tree automorphisms. However, we introduce an infinite series of groups for which that is not so, and describe the kernels of natural homomorphisms of the profinite completions onto the aforementioned closures of respective groups.
22 pages; the statement of financial acknowledgement is slightly changed, and a misprint in the definition of recursive groups is corrected
22 pages; the statement of financial acknowledgement is slightly changed, and a misprint in the definition of recursive groups is corrected