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Related papers: Generating the Twist Subgroup by Involutions

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We construct $(P_2)$-closed groups acting on $T_3$ in which all edge inversions have infinite order. This provides a negative answer to a question posed by Tornier. We also construct a family of $(P_2)$-closed groups for which the smallest…

Group Theory · Mathematics 2026-01-28 Kirwin Hampshire , Florian Lehner , Andrew Wood

We present a framework that connects three interesting classes of groups: the twisted groups (also known as Suzuki-Ree groups), the mixed groups and the exotic pseudo-reductive groups. For a given characteristic p, we construct categories…

Group Theory · Mathematics 2017-03-13 Karsten Naert

A non-zero element of the Lie algebra $\mathfrak{se}(3)$ of the special Euclidean spatial isometry group $SE(3)$ is known as a {\em twist} and the corresponding element of the projective Lie algebra is termed a {\em screw}. Either can be…

Algebraic Geometry · Mathematics 2015-04-03 Mohammed Daher , Peter Donelan

This paper classifies the derivations of twisted group algebras in terms of the generators and defining relations of the group. In particular, we generalize some know results over group algebras to the case of twisted group algebras. We…

Rings and Algebras · Mathematics 2025-10-14 Alvaro Otero Sanchez

We develop a complete obstruction theory for the $\mathbb{Z}_2$-index of a compact connected 4-dimensional manifold with free involution. This $\mathbb{Z}_2$-index, equal to the minimum integer $n$ for which there exists an equivariant map…

Geometric Topology · Mathematics 2024-08-27 Chahrazade Matmat , Christian Blanchet

There is an established bijection between finite-index subgroups Gamma of Gamma(2) and bipartite graphs on surfaces, or, equivalently, certain triples of permutations. We utilize this relationship to study both congruence and noncongruence…

Number Theory · Mathematics 2013-07-29 Erica J. Whitaker

Let N_{g,s} denote the nonorientable surface of genus g with s boundary components. Recently Paris and Szepietowski obtained an explicit finite presentation for the mapping class group M(N_{g,s}) of the surface N_{g,s}, where s\in{0,1} and…

Geometric Topology · Mathematics 2015-01-09 Michal Stukow

In this article, we study the normal generation of the mapping class group. We first show that a mapping class is a normal generator if its restriction on the invariant subsurface normally generates the (pure) mapping class group of the…

Geometric Topology · Mathematics 2023-10-10 Hyungryul Baik , Dongryul M. Kim , Chenxi Wu

We describe the dynamics of a group $\Gamma$ generated by Dehn twists along two filling multi-curves or a family of filling curves on the SU(2)-representation variety of closed surfaces. Consequently, we provide explicit $\Gamma$-invariant…

Geometric Topology · Mathematics 2025-05-06 Fayssal Saadi

It is a classical problem to compute a minimal set of invariant polynomial generating the invariant ring of a finite group as an algebra. We present here an algorithm for the computation of minimal generating sets in the non-modular case.…

Commutative Algebra · Mathematics 2012-10-25 Simon King

We prove that the mapping class group of a closed connected orientable surface of genus $g$ is generated by two elements of order $g$ for $g\geq 6$. Moreover, for $g\geq 7$ we found a generating set of two elements, of order $g$ and $g'$…

Geometric Topology · Mathematics 2020-03-13 Oguz Yildiz

We give a new proof of the theorem of Birman-Powell that the Torelli subgroup of the mapping class group of a closed orientable surface of genus at least 3 is generated by simple homeomorphisms known as bounding pair maps. The key…

Geometric Topology · Mathematics 2012-02-29 Allen Hatcher , Dan Margalit

Using the works of Gervais, Harer, Hatcher and Thurston and others, we show that the mapping class group of a compact orientable surface has a presentation so that the generators are the set of all Dehn twists and the relations are…

Geometric Topology · Mathematics 2007-05-23 Feng Luo

We present an algorithmic framework for computing generators for the ring of invariants of an Artin-Schreier curve. We give explicit invariants for almost all Artin-Schreier curves of genus up to~8 in standard form, and for a handful of…

Number Theory · Mathematics 2026-02-27 Juanita Duque-Rosero , Elisa Lorenzo García , Beth Malmskog , Renate Scheidler

Coxeter groups are a special class of groups generated by involutions. They play important roles in the various areas of mathematics. This survey particularly focuses on how one uses Coxeter groups to construct interesting examples of…

Geometric Topology · Mathematics 2022-02-02 Gye-Seon Lee , Ludovic Marquis

It is known that a presentation of the knot group of a branched twist spin is obtained from a Wirtinger presentation of the original 1-knot group by adding a generator corresponding to a regular orbit of the circle action and a certain…

Geometric Topology · Mathematics 2022-09-26 Mizuki Fukuda

By using a notion of a geometric Dehn twist in $\sharp_k(S^2 \times S^1)$, we prove that when projections of two $\mathbb{Z}$-splittings to the free factor complex are far enough from each other in the free factor complex, Dehn twist…

Group Theory · Mathematics 2018-03-16 Funda Gültepe

For a field $K$ of the second kind with respect to 2 and of characteristic different from 2, we consider the decomposition of the binomials $x^{2^n} - a$ into a product of irreducible factors over $K$ and find the explicit form of the…

Rings and Algebras · Mathematics 2007-05-23 Jordan J. Epitropov , Todor Zh. Mollov , Nako A. Nachev

In this paper, we use a result of Dahmani to show that the Euler class of some power subgroup (the subgroup normally generated by a fixed power of Dehn twist about a non-separating curve) is trivial inside the mapping class group of once…

Geometric Topology · Mathematics 2020-02-18 Lei Chen

We reduce a strong version of the twist conjecture for Artin groups to Artin groups whose defining graphs have no separating vertices. This produces new examples of Artin groups satisfying the conjecture, and sheds more light on the…

Group Theory · Mathematics 2026-05-13 Oli Jones , Giorgio Mangioni , Giovanni Sartori