K(π, 1) and word problems for infinite type Artin–Tits groups, and applications to virtual braid groups

2012 ◽  
Vol 272 (3-4) ◽  
pp. 1339-1364 ◽  
Author(s):  
Eddy Godelle ◽  
Luis Paris
Keyword(s):  
Word Problems ◽  
Braid Groups ◽  
Infinite Type

A GEOMETRIC AND ALGEBRAIC DESCRIPTION OF ANNULAR BRAID GROUPS

2002 ◽  
Vol 12 (01n02) ◽  
pp. 85-97 ◽  
Author(s):  
RICHARD P. KENT ◽  
DAVID PEIFER
Keyword(s):  
Finite Type ◽  
Cyclic Group ◽  
Semidirect Product ◽  
Braid Group ◽  
Braid Groups ◽  
Artin Group ◽  
Infinite Cyclic Group ◽  
Coxeter Graph ◽  
Infinite Type ◽  
Algebraic Description

We provide a new presentation for the annular braid group. The annular braid group is known to be isomorphic to the finite type Artin group with Coxeter graph Bn. Using our presentation, we show that the annular braid group is a semidirect product of an infinite cyclic group and the affine Artin group with Coxeter graph Ãn - 1. This provides a new example of an infinite type Artin group which injects into a finite type Artin group. In fact, we show that the affine braid group with Coxeter graph Ãn - 1 injects into the braid group on n + 1 stings. Recently it has been shown that the braid groups are linear, see [3]. Therefore, this shows that the affine braid groups are also linear.

Pseudo-Anosov Theory

2017 ◽  
Author(s):  
Benson Farb ◽  
Dan Margalit
Keyword(s):  
Braid Groups ◽  
Intersection Numbers ◽  
Branched Covers ◽  
Algebraic Integers ◽  
Dehn Twists ◽  
Mapping Classes ◽  
Dynamical Properties

This chapter focuses on the construction as well as the algebraic and dynamical properties of pseudo-Anosov homeomorphisms. It first presents five different constructions of pseudo-Anosov mapping classes: branched covers, constructions via Dehn twists, homological criterion, Kra's construction, and a construction for braid groups. It then proves a few fundamental facts concerning stretch factors of pseudo-Anosov homeomorphisms, focusing on the theorem that pseudo-Anosov stretch factors are algebraic integers. It also considers the spectrum of pseudo-Anosov stretch factors, along with the special properties of those measured foliations that are the stable (or unstable) foliations of some pseudo-Anosov homeomorphism. Finally, it describes the orbits of a pseudo-Anosov homeomorphism as well as lengths of curves and intersection numbers under iteration.

Schema-Based Instruction Implemented Under Routine Conditions

2019 ◽  
Author(s):  
Corey Peltier ◽  
Mindy E Lingo ◽  
Faye Autry-Schreffler ◽  
Malarie Deardorff ◽  
Leslie Mathews ◽  
...  
Keyword(s):  
Problem Solving ◽  
Word Problems ◽  
Mathematical Problem ◽  
Functional Relation ◽  
Probe Design ◽  
Resource Room ◽  
Group Settings ◽  
Intervention Protocol ◽  
Prior Literature ◽  
Based Instruction

Students identified with a specific learning disability (SLD) experience difficulty with mathematical problem solving. One specific intervention identified as a promising practice for students with a SLD is schema-based instruction (SBI). The current projects aimed to tests the efficacy of SBI under routine conditions. This extends prior literature by (a) using a teacher as the implementer, (b) allowing flexibility in the intervention protocol, (c) condensing the duration of intervention sessions, and (d) providing instruction in small group settings. In addition, we examined student problem solving performance on word problems requiring two-steps and combined schema structures. We used a multiple-probe design across three groups of fifth-grade participants (n = 7) receiving supplemental instruction in a resource room setting. Results indicated a functional relation between SBI and problem-solving performance for all students on simple structure word problems, with the magnitude of effects varying across cases. The NAP, Tau, and BC-SMD effect sizes were used to quantify effects. Implications were discussed in regard to systematic replication and conditions that may impact fidelity.

New Signature Scheme over the Braid Groups

2011 ◽  
Vol 32 (12) ◽  
pp. 2930-2934
Author(s):  
Yun Wei ◽  
Guo-hua Xiong ◽  
Wan-su Bao ◽  
Xing-kai Zhang
Keyword(s):  
Braid Groups ◽  
Signature Scheme

scholarly journals Arithmetic Word Problems Revisited: Cognitive Processes and Academic Performance in Secondary School

2021 ◽  
Vol 11 (4) ◽  
pp. 155
Author(s):  
Gonzalo Duque de Blas ◽  
Isabel Gómez-Veiga ◽  
Juan A. García-Madruga
Keyword(s):  
Academic Performance ◽  
Word Problems ◽  
Spatial Reasoning ◽  
Deductive Reasoning ◽  
Executive Processes ◽  
Mathematical Operation ◽  
Visual Spatial ◽  
And Mathematics ◽  
The One ◽  
Memory Resources

Solving arithmetic word problems is a complex task that requires individuals to activate their working memory resources, as well as the correct performance of the underlying executive processes involved in order to inhibit semantic biases or superficial responses caused by the problem’s statement. This paper describes a study carried out with 135 students of Secondary Obligatory Education, each of whom solved 5 verbal arithmetic problems: 2 consistent problems, whose mathematical operation (add/subtract) and the verbal statement of the problem coincide, and 3 inconsistent problems, whose required operation is the inverse of the one suggested by the verbal term(s). Measures of reading comprehension, visual–spatial reasoning and deductive reasoning were also obtained. The results show the relationship between arithmetic problems and cognitive measures, as well as the ability of these problems to predict academic performance. Regression analyses confirmed that arithmetic word problems were the only measure with significant power of association with academic achievement in both History/Geography (β = 0.25) and Mathematics (β = 0.23).

scholarly journals Crystallographic groups and flat manifolds from surface braid groups

2020 ◽  
pp. 107560
Author(s):  
Daciberg Lima Gonçalves ◽  
John Guaschi ◽  
Oscar Ocampo ◽  
Carolina de Miranda e Pereiro
Keyword(s):  
Braid Groups ◽  
Crystallographic Groups ◽  
Flat Manifolds
Sign in / Sign up

Export Citation Format

Share Document