Collin Bleak
نویسنده
چکیده
My research primarily uses close analysis of the dynamics of a group or semigroup action on a space to discern properties of the group or semigroup. In particular, I am primarily interested in groups of automorphisms of a space and in semigroups of endomorphisms of a space. Supporting this, I have a secondary focus on topological and symbolic dynamics, which itself has lead me to an interest in automata and formal language theory. Most of my past and current work centers around studies of large groups of homeomorphisms. Typical groups of interest are PL(I), Homeo(S), and Homeo(C), the groups of piecewise-linear homeomorphisms of the n-cube I = [0, 1], the group of homeomorphisms of the unit circle S, and the group of homeomorphisms of the Cantor Set C. A consequence of this is that many of my results have direct bearing on the theory of the family of R. Thompson groups F ≤ T ≤ V and their relatives. In the discussion which follows, I will primarily describe the impact of my work on the family of “Thompson-like” groups. Along the way I will also mention other areas impacted by my research.
منابع مشابه
Solvability in Groups of Piecewise-linear Homeomorphisms of the Unit Interval by Collin Bleak
We investigate subgroups of the group PLo(I) of piecewise-linear, orientation preserving homeomorphisms of the unit interval with finitely many breaks in slope, and also subgroups of Thompson’s group F . We find geometric criteria determining the derived length of any such group, and use this criteria to classify the solvable and non-solvable subgroups of PLo(I) and of F . Let H be a subgroup o...
متن کاملA dynamical definition of f.g. virtually free groups
We show that the class of finitely generated virtually free groups is precisely the class of demonstrable subgroups for R. Thompson’s group V . The class of demonstrable groups for V consists of all groups which can embed into V with a natural dynamical behaviour in their induced actions on the Cantor space C2 := {0, 1}. There are also connections with formal language theory, as the class of gr...
متن کاملA Minimal Non-solvable Group of Homeomorphisms
Let PL0(I) represent the group of orientation-preserving piecewise-linear homeomorphisms of the unit interval which admit finitely many breaks in slope, under the operation of composition. We find a non-solvable groupW and show thatW embeds in every non-solvable subgroup of PL0(I). We find mild conditions under which other non-solvable subgroups (B, (≀Z≀), (Z≀), and (≀Z)) embed in subgroups of ...
متن کاملSome undecidability results for asynchronous transducers and the Brin-Thompson group 2V
Using a result of Kari and Ollinger, we prove that the torsion problem for elements of the Brin-Thompson group 2V is undecidable. As a result, we show that there does not exist an algorithm to determine whether an element of the rational group R of Grigorchuk, Nekrashevich, and Sushchanskii has finite order. A modification of the construction gives other undecidability results about the dynamic...
متن کاملStructure Theorems for Groups of Homeomorphisms of the Circle
In this partly expository paper, we study the set A of groups of orientation-preserving homeomorphisms of the circle S which do not admit non-abelian free subgroups. We use classical results about homeomorphisms of the circle and elementary dynamical methods to derive various new and old results about the groups in A. Of the known results, we include some results from a family of results of Bek...
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