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Related papers: Stable Commutator Length in Amalgamated Free Produ…

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We introduce stable reflection length in Coxeter groups, as a way to study the asymptotic behaviour of reflection length. This creates connections to other well-studied stable length functions in groups, namely stable commutator length and…

Group Theory · Mathematics 2025-04-02 Francesco Fournier-Facio , Marco Lotz , Timothée Marquis

The main result of this paper is an explicit construction of the free commutative skew brace -- that is, a skew brace whose circle group is commutative -- on an arbitrary generating set $X$. We embed this object into a set of rational…

Group Theory · Mathematics 2025-06-25 Thomas Letourmy

A smooth cuboid can be identified with a $3\times 3$ matrix of linear forms, with coefficients in a field $K$, whose determinant describes a smooth cubic in the projective plane. To each such matrix one can associate a group scheme over…

Group Theory · Mathematics 2025-04-23 Joshua Maglione , Mima Stanojkovski

Let $w$ be a word in a free group. As was revealed by Magee and Puder in [arXiv:1802.04862], the stable commutator length (scl) of $w$, a well-known topological invariant, can also be defined in terms of certain stable Fourier coefficients…

Group Theory · Mathematics 2025-10-22 Doron Puder , Yotam Shomroni

We prove that cyclic subgroup separability is preserved under exponential completion for groups that belong to a class that includes all coherent RAAGs and toral relatively hyperbolic groups; we do so by exploiting the structure of these…

Group Theory · Mathematics 2021-01-27 Jonathan Fruchter

We investigate which free constructions (amalgamated products and HNN-extensions) over word hyperbolic groups produce groups that are again word hyperbolic. A complete answer is obtained for the case when the amalgamated subgroups are…

Group Theory · Mathematics 2008-02-03 Olga Kharlampovich , Alexey Myasnikov

We extend Matui's notion of almost finiteness to general etale groupoids and show that the reduced groupoid C*-algebras of minimal almost finite groupoids have stable rank one. The proof follows a new strategy, which can be regarded as a…

Operator Algebras · Mathematics 2020-11-10 Yuhei Suzuki

This paper is the 10th in a sequence on the structure of sets of solutions to systems of equations over groups, projections of such sets (Diophantine sets), and the structure of definable sets over few classes of groups. In the 10th paper…

Group Theory · Mathematics 2010-12-02 Zlil Sela

The $K$-groups of the crossed product of the rotation C*-algebra $A_\theta$ by free and amalgamated products of the cyclic groups $\mathbb Z_n$, for $n=2,3,4,6$, are calculated. The actions here arise from the canonical actions of these…

Operator Algebras · Mathematics 2018-09-26 Sam Walters

We investigate stabilizers of finite sets of rational points in Cantor space for the Higman-Thompson groups $V_{n,r}$. We prove that the pointwise stabilizer is an iterated ascending HNN extension of $V_{n,q}$ for any $q\geq 1$. We also…

Group Theory · Mathematics 2021-04-14 James Belk , James Hyde , Francesco Matucci

The size of minimal generating set for commutator of Sylow 2-subgroup of alternating group was found. Given a permutational wreath product of finite cyclic groups sequence we prove that the commutator width of such groups is 1 and we…

Group Theory · Mathematics 2020-01-09 Ruslan Skuratovskii

A classification of the ways in which an element of a free group can be expressed as a product of commutators or as a product of squares is given. This is then applied to some particular classes of elements. Finally, a question about…

Group Theory · Mathematics 2008-02-03 Leo P. Comerford , Charles C. Edmunds

Let $\Gamma$ be a finite index subgroup of the mapping class group $MCG(\Sigma)$ of a closed orientable surface $\Sigma$, possibly with punctures. We give a precise condition (in terms of the Nielsen-Thurston decomposition) when an element…

Group Theory · Mathematics 2013-06-12 Mladen Bestvina , Ken Bromberg , Koji Fujiwara

We consider the problem of counting commuting r-tuples of elements of the symmetric group S_n, i.e. computing |Hom(Z^r,S_n)|. The cases r=1,2 are well-known; a product formula for the case r=3 was conjectured by Adams-Watters and later…

Combinatorics · Mathematics 2013-04-11 Tad White

We compute the rational stable homology of the automorphism groups of free nilpotent groups. These groups interpolate between the general linear groups over the ring of integers and the automorphism groups of free groups, and we employ…

K-Theory and Homology · Mathematics 2019-08-02 Markus Szymik

Let $G$ be the generalized free product of two groups with an amalgamated subgroup. We propose an approach that allows one to use results on the residual $p$-finiteness of $G$ for proving that this generalized free product is residually a…

Group Theory · Mathematics 2024-05-24 E. V. Sokolov

We prove that the nilpotent product of a set of groups $A_{1},\dots, A_{s}$ has finite palindromic width if and only if the palindromic widths of $A_{i}, i=1,\dots, s,$ are finite. We give a new proof that the commutator width of $F_n \wr…

Group Theory · Mathematics 2018-01-23 Valeriy G. Bardakov , Oleg V. Bryukhanov , Krishnendu Gongopadhyay

We show that the set $SCL^{rp}$ of stable commutator lengths on recursively presented groups equals the set of non-negative right-computable numbers. Hence all non-negative algebraic or computable numbers are in $SCL^{rp}$ and $SCL^{rp}$ is…

Group Theory · Mathematics 2019-09-04 Nicolaus Heuer

This paper is devoted to the proof of the property of order separability for free product of free groups with maximal cyclic amalgamated subgroups.

Group Theory · Mathematics 2010-07-09 Vladimir V. Yedynak

By employing the external Kasparov product, Hawkins, Skalski, White and Zacharias constructed spectral triples on crossed product C$^\ast$-algebras by equicontinuous actions of discrete groups. They further raised the question for whether…

Operator Algebras · Mathematics 2026-01-28 Mario Klisse