Results 11 to 20 of about 420 (31)
Deforming cubulations of hyperbolic groups
Journal of Topology, Volume 14, Issue 3, Page 877-912, September 2021., 2021 Abstract We describe a procedure to deform cubulations of hyperbolic groups by ‘bending hyperplanes’. Our construction is inspired by related constructions like Thurston's Mickey Mouse example, walls in fibred hyperbolic 3‐manifolds and free‐by‐Z groups, and Hsu–Wise turns.
Elia Fioravanti, Mark Hagen
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(Un)distorted stabilisers in the handlebody group
Journal of Topology, Volume 14, Issue 2, Page 460-487, June 2021., 2021 Abstract We study geometric properties of stabilisers in the handlebody group. We find that stabilisers of meridians are undistorted, while stabilisers of primitive curves or annuli are exponentially distorted for large enough genus.
Sebastian Hensel
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Quasi‐isometric diversity of marked groups
Journal of Topology, Volume 14, Issue 2, Page 488-503, June 2021., 2021 Abstract We use basic tools of descriptive set theory to prove that a closed set S of marked groups has 2ℵ0 quasi‐isometry classes, provided that every non‐empty open subset of S contains at least two non‐quasi‐isometric groups. It follows that every perfect set of marked groups having a dense subset of finitely presented groups contains 2ℵ0 quasi ...
A. Minasyan, D. Osin, S. Witzel
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Calculating the virtual cohomological dimension of the automorphism group of a RAAG
Bulletin of the London Mathematical Society, Volume 53, Issue 1, Page 259-273, February 2021., 2021 Abstract We describe an algorithm to find the virtual cohomological dimension of the automorphism group of a right‐angled Artin group. The algorithm works in the relative setting; in particular, it also applies to untwisted automorphism groups and basis‐conjugating automorphism groups.
Matthew B. Day +2 more
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Injectivity results for coarse homology theories
Proceedings of the London Mathematical Society, Volume 121, Issue 6, Page 1619-1684, December 2020., 2020 Abstract We show injectivity results for assembly maps using equivariant coarse homology theories with transfers. Our method is based on the descent principle and applies to a large class of linear groups or, more generally, groups with finite decomposition complexity.
Ulrich Bunke +3 more
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Homotopy type of the complex of free factors of a free group
Proceedings of the London Mathematical Society, Volume 121, Issue 6, Page 1737-1765, December 2020., 2020 Abstract We show that the complex of free factors of a free group of rank n⩾2 is homotopy equivalent to a wedge of spheres of dimension n−2. We also prove that for n⩾2, the complement of (unreduced) Outer space in the free splitting complex is homotopy equivalent to the complex of free factor systems and moreover is (n−2)‐connected.
Benjamin Brück, Radhika Gupta
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Finite‐dimensional approximation properties for uniform Roe algebras
Journal of the London Mathematical Society, Volume 102, Issue 2, Page 623-644, October 2020., 2020 Abstract We study property A for metric spaces X with bounded geometry introduced by Guoliang Yu. Property A is an amenability‐type condition, which is less restrictive than amenability for groups. The property has a connection with finite‐dimensional approximation properties in the theory of operator algebras. It has been already known that property A
Hiroki Sako
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Exponential growth of some iterated monodromy groups
Proceedings of the London Mathematical Society, Volume 116, Issue 6, Page 1489-1518, June 2018., 2018 Abstract Iterated monodromy groups of postcritically finite rational maps form a rich class of self‐similar groups with interesting properties. There are examples of such groups that have intermediate growth, as well as examples that have exponential growth. These groups arise from polynomials.
Mikhail Hlushchanka, Daniel Meyer
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A remark on the intersection of the conjugates of the base of quasi‐HNN groups
International Journal of Mathematics and Mathematical Sciences, Volume 2004, Issue 25, Page 1293-1297, 2004., 2004 Quasi‐HNN groups can be characterized as a generalization of HNN groups. In this paper, we show that if G∗ is a quasi‐HNN group of base G, then either any two conjugates of G are identical or their intersection is contained in a conjugate of an associated subgroup of G.
R. M. S. Mahmood
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On centralizers of elements of groups acting on trees with inversions
International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 20, Page 1241-1249, 2003., 2003 A subgroup H of a group G is called malnormal in G if it satisfies the condition that if g ∈ G and h ∈ H, h ≠ 1 such that ghg−1 ∈ H, then g ∈ H. In this paper, we show that if G is a group acting on a tree X with inversions such that each edge stabilizer is malnormal in G, then the centralizer C(g) of each nontrivial element g of G is in a vertex ...
R. M. S. Mahmood
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