Results 11 to 20 of about 87 (78)
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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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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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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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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Teichmuller Space and Related Topics : Proceedings of the workshop on Geometry, January 20, 2011, JOSAI UNIVERSITY [PDF]
, 2012 We calculate the growth functions of noncompact 3-dimensional hyperbolic Coxeter groups with 4 and 5 generators.Teichmuller Space and Related Topics : Proceedings of the workshop on Geometry, January 20, 2011, JOSAI UNIVERSITY / edited by Kiyoko ...
小森, 洋平, 梅本, 悠莉子
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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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Generating numbers of rings graded by amenable and supramenable groups
, 2023 A ring has unbounded generating number (UGN) if,for every positive integer , there is no -module epimorphism → +1. For a ring = ⨁g∈ g gradedby a group such that the base ring 1 has UGN, weidentify several sets of conditions under which mustalso have
Lorensen, Karl +5 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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International Journal of Mathematics and Mathematical Sciences, Volume 31, Issue 12, Page 731-743, 2002., 2002 We extend the structure theorem for the subgroups of the class of HNN groups to a new class of groups called quasi‐HNN groups. The main technique used is the subgroup theorem for groups acting on trees with inversions.
R. M. S. Mahmood, M. I. Khanfar
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