Results 11 to 20 of about 45 (45)
Cusps, Kleinian groups, and Eisenstein series
Forum of Mathematics, Sigma, 2023 We study the Eisenstein series associated to the full rank cusps in a complete hyperbolic manifold. We show that given a Kleinian group $\Gamma
Beibei Liu, Shi Wang
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On subset sum problem in branch groups [PDF]
Groups, Complexity, Cryptology, 2020 We consider a group-theoretic analogue of the classic subset sum problem. In this brief note, we show that the subset sum problem is NP-complete in the first Grigorchuk group.
Andrey Nikolaev, Alexander Ushakov
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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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Curve graphs for Artin–Tits groups of type B, A∼ and C∼ are hyperbolic
Transactions of the London Mathematical Society, 2021 The graph of irreducible parabolic subgroups is a combinatorial object associated to an Artin–Tits group A defined so as to coincide with the curve graph of the (n+1)‐times punctured disk when A is Artin's braid group on (n+1) strands.
Matthieu Calvez +1 more
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The Asymptotic Statistics of Random Covering Surfaces
Forum of Mathematics, Pi, 2023 Let $\Gamma _{g}$ be the fundamental group of a closed connected orientable surface of genus $g\geq 2$ . We develop a new method for integrating over the representation space $\mathbb {X}_{g,n}=\mathrm {Hom}(\Gamma _{g},S_{n})$ , where
Michael Magee, Doron Puder
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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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Growth functions for some uniformly amenable groups
Open Mathematics, 2017 We present a simple constructive proof of the fact that every abelian discrete group is uniformly amenable. We improve the growth function obtained earlier and find the optimal growth function in a particular case.
Dronka Janusz +3 more
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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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