scholarly journals EXTRASPECIAL 2-GROUPS AND IMAGES OF BRAID GROUP REPRESENTATIONS

2006 ◽  
Vol 15 (04) ◽  
pp. 413-427 ◽  
Author(s):  
JENNIFER M. FRANKO ◽  
ERIC C. ROWELL ◽  
ZHENGHAN WANG
Keyword(s):  
Finite Groups ◽  
Braid Group ◽  
Braid Groups ◽  
Baxter Equation ◽  
Group Representations ◽  
Specific Solution ◽  
Link Invariants

We investigate a family of (reducible) representations of the braid groups [Formula: see text] corresponding to a specific solution to the Yang–Baxter equation. The images of [Formula: see text] under these representations are finite groups, and we identify them precisely as extensions of extra-special 2-groups. The decompositions of the representations into their irreducible constituents are determined, which allows us to relate them to the well-known Jones representations of [Formula: see text] factoring over Temperley–Lieb algebras and the corresponding link invariants.

FERMIONS AND LINK INVARIANTS

1992 ◽  
Vol 07 (supp01a) ◽  
pp. 493-532 ◽  
Author(s):  
L. Kauffman ◽  
H. Saleur
Keyword(s):  
Braid Group ◽  
Degrees Of Freedom ◽  
Knot Theory ◽  
Alexander Polynomial ◽  
Baxter Equation ◽  
Group Representations ◽  
R Matrix ◽  
Link Invariants ◽  
Linear Representations ◽  
State Models

This paper deals with various aspects of knot theory when fermionic degrees of freedom are taken into account in the braid group representations and in the state models. We discuss how the Ř matrix for the Alexander polynomial arises from the Fox differential calculus, and how it is related to the quantum group Uqgl(1,1). We investigate new families of solutions of the Yang Baxter equation obtained from "linear" representations of the braid group and exterior algebra. We study state models associated with Uqsl(n,m), and in the case n=m=1 a state model for the multivariable Alexander polynomial. We consider invariants of links in solid handlebodies and show how the non trivial topology lifts the boson fermion degeneracy that is present in S3. We use "gauge like" changes of basis to obtain invariants in thickened surfaces Σ×[0,1].

scholarly journals Finiteness for mapping class group representations from twisted Dijkgraaf–Witten theory

2018 ◽  
Vol 27 (06) ◽  
pp. 1850043 ◽  
Author(s):  
Paul P. Gustafson
Keyword(s):  
Braid Group ◽  
Mapping Class Group ◽  
Class Group ◽  
Braid Groups ◽  
Fusion Category ◽  
Mapping Class ◽  
Group Representations ◽  
Colored Graphs ◽  
Finite Image ◽  
Spanning Set

We show that any twisted Dijkgraaf–Witten representation of a mapping class group of an orientable, compact surface with boundary has finite image. This generalizes work of Etingof et al. showing that the braid group images are finite [P. Etingof, E. C. Rowell and S. Witherspoon, Braid group representations from twisted quantum doubles of finite groups, Pacific J. Math. 234 (2008)(1) 33–42]. In particular, our result answers their question regarding finiteness of images of arbitrary mapping class group representations in the affirmative. Our approach is to translate the problem into manipulation of colored graphs embedded in the given surface. To do this translation, we use the fact that any twisted Dijkgraaf–Witten representation associated to a finite group [Formula: see text] and 3-cocycle [Formula: see text] is isomorphic to a Turaev–Viro–Barrett–Westbury (TVBW) representation associated to the spherical fusion category [Formula: see text] of twisted [Formula: see text]-graded vector spaces. The representation space for this TVBW representation is canonically isomorphic to a vector space of [Formula: see text]-colored graphs embedded in the surface [A. Kirillov, String-net model of Turaev-Viro invariants, Preprint (2011), arXiv:1106.6033 ]. By analyzing the action of the Birman generators [J. Birman, Mapping class groups and their relationship to braid groups, Comm. Pure Appl. Math. 22 (1969) 213–242] on a finite spanning set of colored graphs, we find that the mapping class group acts by permutations on a slightly larger finite spanning set. This implies that the representation has finite image.

An infinite family of braid group representations in automorphism groups of free groups

2020 ◽  
Vol 29 (10) ◽  
pp. 2042007
Author(s):  
Wonjun Chang ◽  
Byung Chun Kim ◽  
Yongjin Song
Keyword(s):  
Braid Group ◽  
Class Group ◽  
Automorphism Groups ◽  
Free Groups ◽  
Infinite Family ◽  
Braid Groups ◽  
Mapping Class ◽  
Group Representations ◽  
Class Groups ◽  
Branched Coverings

The [Formula: see text]-fold ([Formula: see text]) branched coverings on a disk give an infinite family of nongeometric embeddings of braid groups into mapping class groups. We, in this paper, give new explicit expressions of these braid group representations into automorphism groups of free groups in terms of the actions on the generators of free groups. We also give a systematic way of constructing and expressing these braid group representations in terms of a new gadget, called covering groupoid. We prove that each generator [Formula: see text] of braid group inside mapping class group induced by [Formula: see text]-fold covering is the product of [Formula: see text] Dehn twists on the surface.

scholarly journals BRAID GROUP REPRESENTATIONS ARISING FROM THE YANG–BAXTER EQUATION

2010 ◽  
Vol 19 (04) ◽  
pp. 525-538 ◽  
Author(s):  
JENNIFER M. FRANKO
Keyword(s):  
Group Algebra ◽  
Braid Group ◽  
Roots Of Unity ◽  
Baxter Equation ◽  
Group Representations ◽  
Link Invariant

This paper aims to determine the images of the braid group under representations afforded by the Yang–Baxter equation when the solution is a non-trivial 4 × 4 matrix. Making the assumption that all the eigenvalues of the Yang–Baxter solution are roots of unity, leads to the conclusion that all the images are finite. Using results of Turaev, we have also identified cases in which one would get a link invariant. Finally, by observing the group algebra generated by the image of the braid group sometimes factor through known algebras, in certain instances we can identify the invariant as particular specializations of a known invariant.

SET-THEORETIC YANG–BAXTER SOLUTIONS VIA FOX CALCULUS

2006 ◽  
Vol 15 (08) ◽  
pp. 949-956 ◽  
Author(s):  
J. SCOTT CARTER ◽  
MASAHICO SAITO
Keyword(s):  
Free Group ◽  
Braid Group ◽  
Baxter Equation ◽  
Group Representations ◽  
Group Automorphisms ◽  
Free Group Automorphisms

We construct solutions to the set–theoretic Yang–Baxter equation using braid group representations in free group automorphisms and their Fox differentials. The method resembles the extensions of groups and quandles.

NEW SOLUTIONS OF THE YANG-BAXTER EQUATION AND THEIR YANG-BAXTERIZATION

1991 ◽  
Vol 06 (04) ◽  
pp. 559-576 ◽  
Author(s):  
M. COUTURE ◽  
Y. CHENG ◽  
M.L. GE ◽  
K. XUE
Keyword(s):  
Lie Algebras ◽  
Braid Group ◽  
Classical Limit ◽  
Usual Sense ◽  
Baxter Equation ◽  
Group Representations ◽  
Simple Lie Algebras

Through the examples associated with simple Lie algebras B2, C2 and D2, an approach of constructing new solutions of the spectral-independent Yang-Baxter equation (i.e. the braid group representations) was shown. These new solutions possess some particular features, such as that they do not have the classical limit in the usual sense of Refs. 2, 5, etc., and give rise to the new solutions of the x-dependent Yang-Baxter equation by using the Yang-Baxterization prescription.

scholarly journals Geometric Presentations of Braid Groups for Particles on a Graph

2021 ◽  
Author(s):  
Byung Hee An ◽  
Tomasz Maciazek
Keyword(s):  
Braid Group ◽  
Planar Graphs ◽  
Braid Groups ◽  
Quantum Statistics ◽  
Simple Cycle ◽  
Full Description ◽  
Baxter Equation ◽  
Connected Graphs ◽  
Star Graphs ◽  
Graph Theoretic

AbstractWe study geometric presentations of braid groups for particles that are constrained to move on a graph, i.e. a network consisting of nodes and edges. Our proposed set of generators consists of exchanges of pairs of particles on junctions of the graph and of certain circular moves where one particle travels around a simple cycle of the graph. We point out that so defined generators often do not satisfy the braiding relation known from 2D physics. We accomplish a full description of relations between the generators for star graphs where we derive certain quasi-braiding relations. We also describe how graph braid groups depend on the (graph-theoretic) connectivity of the graph. This is done in terms of quotients of graph braid groups where one-particle moves are put to identity. In particular, we show that for 3-connected planar graphs such a quotient reconstructs the well-known planar braid group. For 2-connected graphs this approach leads to generalisations of the Yang–Baxter equation. Our results are of particular relevance for the study of non-abelian anyons on networks showing new possibilities for non-abelian quantum statistics on graphs.

scholarly journals Link Invariants Associated with Gauge Equivalent Solutions of the Yang–Baxter Equation: The One-Parameter Family of Minimal Typical Representations of Uq[gl(2|1)]

2003 ◽  
Vol 12 (06) ◽  
pp. 739-749
Author(s):  
Jon R. Links ◽  
David de Wit
Keyword(s):  
Braid Group ◽  
Parameter Family ◽  
Baxter Equation ◽  
Link Invariants ◽  
State Models ◽  
The One ◽  
Quantum Superalgebra

In this paper we investigate the construction of state models for link invariants using representations of the braid group obtained from various gauge choices for a solution of the trigonometric Yang–Baxter equation. Our results show that it is possible to obtain invariants of regular isotopy (as defined by Kauffman) which may not be ambient isotopic. We illustrate our results with explicit computations using solutions of the trigonometric Yang–Baxter equation associated with the one-parameter family of minimal typical representations of the quantum superalgebra Uq[gl(2|1)]. We have implemented MATHEMATICA code to evaluate the invariants for all prime knots up to 10 crossings.

scholarly journals GENERALIZED YANG–BAXTER EQUATIONS AND BRAIDING QUANTUM GATES

2012 ◽  
Vol 21 (09) ◽  
pp. 1250087 ◽  
Author(s):  
REBECCA S. CHEN
Keyword(s):  
Braid Group ◽  
Knot Theory ◽  
Information Science ◽  
Quantum Gates ◽  
Quantum Computers ◽  
Baxter Equation ◽  
Group Representations ◽  
Ongoing Research ◽  
Topological Quantum ◽  
Mathematics And Physics

Solutions to the Yang–Baxter equation — an important equation in mathematics and physics — and their afforded braid group representations have applications in fields such as knot theory, statistical mechanics, and, most recently, quantum information science. In particular, unitary representations of the braid group are desired because they generate braiding quantum gates. These are actively studied in the ongoing research into topological quantum computing. A generalized Yang–Baxter equation was proposed a few years ago by Eric Rowell et al. By finding solutions to the generalized Yang–Baxter equation, we obtain new unitary braid group representations. Our representations give rise to braiding quantum gates and thus have the potential to aid in the construction of useful quantum computers.

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