The skein polynomial of closed 3-braids

通过辫子方法计算 $S^1 \times S^2$ 的 HOMFLYPT 绞线模

The HOMFLYPT skein module of $S^1 \times S^2$ via braids

本文通过辫子理论技术，将实心环面中的 Lambropoulou 不变量推广到 $S^1 \times S^2$，并求解无穷方程组，从而完全确定其 HOMFLYPT 绞线模的结构：自由部分仅由空链环生成，其余元素均为挠元。

A simple algorithm to compute link polynomials defined by using skein relations

We give a simple and practical algorithm to compute the link polynomials, which are defined according to the skein relations. Our method is based on a new total order on the set of all braid representatives. As by-product a new complete link invariant are obtained.

The Kauffman bracket skein module of the lens spaces via unoriented braids

In this paper we develop a braid theoretic approach for computing the Kauffman bracket skein module of the lens spaces $L(p,q)$, KBSM($L(p,q)$), for $q\neq 0$. For doing this, we introduce a new concept, that of an {\it unoriented braid}. Unoriented braids are obtained from standard braids by ignoring the natural top-to-bottom orientation of the strands. We first define the {\it generalized Temperley-Lieb algebra of type B}, $TL_{1, n}$, which is related to the knot theory of the solid torus ST, and we obtain the universal Kauffman bracket type invariant, $V$, for knots and links in ST, via a …

$A_2$ Skein Representations of Pure Braid Groups

We define a family of representations $\{ρ_n\}_{n\geq 0}$ of a pure braid group $P_{2k}$. These representations are obtained from an action of $P_{2k}$ on a certain type of $A_2$ web space with color $n$. The $A_2$ web space is a generalization of the Kauffman bracket skein module of a disk with marked points on its boundary. We also introduce a triangle-free basis of such an $A_2$ web space and calculate matrix representations of $ρ_n$ about the standard generators of $P_{2k}$.

基于辫子的 $S^1\times S^2$ 的考夫曼括号扭结模

The Kauffman bracket skein module of $S^1\times S^2$ via braids

该研究提出两种基于辫子计算 $S^1\times S^2$ 的考夫曼括号扭结模的方法，证明其非无挠且自由部由平凡纽结生成，还通过图解法得到其挠部的闭式公式。

Coloring Link Diagrams And Conway-type Polynomial Of Braids

In this paper we define and present a simple combinatorial formula for a 3-variable Laurent polynomial invariant of conjugacy classes in Artin braid group $B_m$. We show that this Laurent polynomial satisfies the Conway skein relation and its coefficients are Vassiliev invariants of braids.

The Kauffman bracket skein module of the complement of $(2, 2p+1)$-torus knots via braids

In this paper we compute the Kauffman bracket skein module of the complement of $(2, 2p+1)$-torus knots, $KBSM(T_{(2, 2p+1)}^c)$, via braids. We start by considering geometric mixed braids in $S^3$, the closure of which are mixed links in $S^3$ that represent links in the complement of $(2, 2p+1)$-torus knots, $T_{(2, 2p+1)}^c$. Using the technique of parting and combing, we obtain algebraic mixed braids, that is, mixed braids that belong to the mixed braid group $B_{2, n}$ and that are followed by their ``coset'' part, that represents $T_{(2, 2p+1)}^c$. In that way we show that links in $T_{(…

HOMFLYPT skein sub-modules of the lens spaces $L(p, 1)$

In this paper we work toward the HOMFLYPT skein module of $L(p, 1)$, $\mathcal{S}(L(p,1))$, via braids. Our starting point is the linear Turaev-basis, $Λ^{\prime}$, of the HOMFLYPT skein module of the solid torus ST, $\mathcal{S}({\rm ST})$, which can be decomposed as the tensor product of the "positive" ${Λ^{\prime}}^+$ and the "negative" ${Λ^{\prime}}^-$ sub-modules, and the Lambropoulou invariant, $X$, for knots and links in ST, that captures $S({\rm ST})$. It is a well-known result by now that $\mathcal{S}(L(p, 1))=\frac{\mathcal{S}(ST)}{<bbm's>}$, where bbm's (braid band moves) denotes th…

闭合3辫的HFK的次顶项

Second-to-Top Term of \hat{HFK} of Closed 3-Braids

本文通过 skein 精确序列等技术，计算闭合3辫的HFK次顶项，并验证了Sivek的秩不等式猜想。

Skein theories for virtual tangles

In this paper, we use skein-theoretic techniques to classify all virtual knot polynomials and trivalent graph invariants with certain smallness conditions. The first half of the paper classifies all virtual knot polynomials giving non-trivial invariants strictly smaller than the one given by the Higman-Sims spin model. In particular, we exhibit a family of skein theories coming from $\text{Rep}(O(2))$ with an interesting braiding. In addition, all skein theories of oriented virtual tangles with some smallness conditions are classified. In the second half of the paper, we classify all non-trivi…

Representations of the Kauffman bracket skein algebra III: closed surfaces and naturality

This is the third article in the series begun with [BonWon3, BonWon4], devoted to finite-dimensional representations of the Kauffman bracket skein algebra of an oriented surface $S$. In [BonWon3] we associated a classical shadow to an irreducible representation $ρ$ of the skein algebra, which is a character $r_ρ\in \mathcal R_{\mathrm{SL}_2(\mathbb C)}(S)$ represented by a group homomorphism $π_1(S) \to \mathrm{SL}_2(\mathbb C)$. The main result of the current article is that, when the surface $S$ is closed, every character $r\in \mathcal R_{\mathrm{SL}_2(\mathbb C)}(S)$ occurs as the classica…

A property of the skein polynomial with an application to contact geometry

We prove a finiteness property of the values of the skein polynomial of homogeneous knots which allows to establish large classes of such knots to have arbitrarily unsharp Bennequin inequality (for the Thurston-Bennequin invariant of any of their Legendrian embeddings in the standard contact structure of R^3), and a give a short proof that there are only finitely many among these knots that have given genus and given braid index.

Braid equivalence in 3-manifolds with rational surgery description

In this paper we describe braid equivalence for knots and links in a 3-manifold $M$ obtained by rational surgery along a framed link in $S^3$. We first prove a sharpened version of the Reidemeister theorem for links in $M$. We then give geometric formulations of the braid equivalence via mixed braids in $S^3$ using the $L$-moves and the braid band moves. We finally give algebraic formulations in terms of the mixed braid groups $B_{m,n}$ using cabling and the techniques of parting and combing for mixed braids. We also provide concrete formuli of the braid equivalence in the case where $M$ is a …

Recurrence relation for HOMFLY polynomial and rational specializations

Turning the skein relation for HOMFLY into a Fibonacci recurrence, we prove that there are only three rational specializations of HOMFLY polynomial: Alexander-Conway, Jones, and a new one. Using the recurrence relation, we find general and relative expansion formulae and rational generating functions for Alexander-Conway polynomial and the new polynomial, which reduce the computations to closure of simple braids, a subset of square free braids; HOMFLY polynomials of these simple braids are also computed. Algebraic independence of these three polynomials is proved.

On the crossing number of positive knots and braids and braid index criteria of Jones and Morton-Williams-Franks

We give examples of knots with some unusual properties of the crossing number of positive diagrams or strand number of positive braid representations. In particular we show that positive braid knots may not have positive minimal (strand number) braid representations, giving a counterpart to results of Franks-Williams and Murasugi. Other examples answer questions of Cromwell on homogeneous and (partially) of Adams on almost alternating knots. We give a counterexample to, and a corrected version of a theorem of Jones on the Alexander polynomial of 4-braid knots. We also give an example of a knot…

The Witten-Reshetikhin-Turaev representation of the Kauffman skein algebra

For A a primitive 2N-root of unity with N odd, the Witten-Reshetikhin-Turaev topological quantum field theory provides a representation of the Kauffman skein algebra of a closed surface. We show that this representation is irreducible and we compute its classical shadow, in the sense of earlier work of the authors (arXiv:1206.1638).

闭3-流形的绞纱模在特征簇上定义线丛

Skein modules of closed 3 manifolds define line bundles over character varieties

本文利用Frobenius态射将闭3-流形在奇数阶单位根处的绞纱模解释为SL2特征概形上凝聚层的全局截面空间，并证明当特征概形约化时该凝聚层为线丛。

Lower and Upper Bounds for Positive Bases of Skein Algebras

We show that the if a sequence of normalized polynomials gives rise to a positive basis of the skein algebra of a surface, then it is sandwiched between the two types of Chebyshev polynomials. For the closed torus, we show that the normalized sequence of Chebyshev polynomials of type one $(\hat{T}_n)$ is the only one which gives a positive basis.

小曲面的$\rm{PGL}_2$ skein代数

$\rm{PGL}_2$ skein algebras of small surfaces

本文研究小曲面（闭环面与一次穿孔环面）的$\rm{PGL}_2$ skein代数，给出显式有限表示、显式基及其乘法结构，并计算自然映射的核与代数中心，结果依赖于量子参数$q$。

Tied Links

In this paper we introduce the tied links, i.e. ordinary links provided with some ties between strands. The motivation for introducing such objects originates from a diagrammatical interpretation of the defining generators of the so-called algebra of braids and ties; indeed, one half of such generators can be interpreted as the usual generators of the braid algebra, and the remaining generators can be interpreted as ties between consecutive strands; this interpretation leads the definition of tied braids. We define an invariant polynomial for the tied links via a skein relation. Furthermore, w…

从 Dehn-Thurston 坐标看曲面辫代数到量子环面的嵌入

An embedding of skein algebras of surfaces into quantum tori from Dehn-Thurston coordinates

本文利用辫代数在柄体辫模上的作用，构造了曲面 Kauffman 括号辫代数到局部化量子环面的嵌入，并借此研究了单位根处的表示，给出了 Bonahon-Wong 唯一性猜想的新证明及唯一表示的显式重构方法。

结绳理论与Links-Gould多项式

Skein theory for the Links-Gould polynomial

本文通过建立立方辫型结绳理论，证明Links-Gould多项式和$V_1$-多项式相等，并揭示其在多项式不变量中的应用与特性。

单孔环面 Skein 代数上乘法的快速算法

Fast Algorithm for Multiplication on the Skein Algebra of One-hole Torus

针对单孔环面 skein 代数乘法复杂度高的问题，提出多项式时间算法并给出低交叉数情形的闭式公式，显著提升计算效率。

曲面skein代数的代数生成元

Algebraic generators of the skein algebra of a surface

本文证明具有负欧拉示性数等条件的曲面在有理函数域上的skein代数可由关联其映射类群生成元的有限条简单闭曲线代数生成，并据此猜想该代数的展示。

The finiteness conjecture for skein modules

We give a new, algebraically computable formula for skein modules of closed 3-manifolds via Heegaard splittings. As an application, we prove that skein modules of closed 3-manifolds are finite-dimensional, resolving in the affirmative a conjecture of Witten.

Properties of closed 3-braids

We show that 3-braid links with given (non-zero) Alexander or Jones polynomial are finitely many, and can be effectively determined. We classify among closed 3-braids strongly quasipositive and fibered ones, and show that 3-braid links have a unique incompressible Seifert surface. We also classify the positive braid words with Morton-Williams-Franks bound 3 and show that closed positive braids of braid index 3 are closed positive 3-braids. For closed braids on more strings, we study the alternating links occurring. In particular we classify those of braid index 4, and show that their Morton-Wi…

Semi-Adequate Closed Braids and Volume

In this paper, we show that the volumes for a family of A-adequate closed braids can be bounded above and below in terms of the twist number, the number of braid strings, and a quantity that can be read from the combinatorics of a given closed braid diagram. We also show that the volumes for many of these closed braids can be bounded in terms of a single stable coefficient of the colored Jones polynomial, thus showing that this collection of closed braids satisfies a Coarse Volume Conjecture. By expanding to a wider family of closed braids, we also obtain volume bounds in terms of the number o…

亏格2的纽结代数的表示

Presentations of skein algebras of genus 2

该研究给出亏格2的闭或单洞定向曲面的考夫曼括号纽结代数的表示，为亏格大于1的相关问题提供了首个此类结果。

Closed 3-braids are nearly fibred

Ozsváth and Szabó conjectured that knot Floer homology detects fibred links. We will verify this conjecture for closed 3-braids, by classifying fibred closed 3-braids. In particular, given a nontrivial closed 3-braid, either it is fibred, or it differs from a fibred link by a half twist. The proof uses Gabai's method of disk decomposition.

Braid ordering and the geometry of closed braid

The relationships between braid ordering and the geometry of its closure is studied. We prove that if an essential closed surface $F$ in the complements of closed braid has relatively small genus with respect to the Dehornoy floor of the braid, $F$ is circular-foliated in a sense of Birman-Menasco's Braid foliation theory. As an application of the result, we prove that if Dehornoy floor of braids are larger than three, Nielsen-Thurston classification of braids and the geometry of their closure's complements are in one-to-one correspondence. Using this result, we construct infinitely many hyper…

The dealternating number and the alternation number of a closed 3-braid

We give an upper bound for the dealternating number of a closed 3-braid. As applications, we determine the dealternating numbers, the alternation numbers and the Turaev genera of some closed positive 3-braids. We also show that there exist infinitely many positive knots with any dealternating number (or any alternation number) and any braid index.

Crossing changes in closed 3-braid diagrams

A crossing in a knot is nugatory if changing the crossing does not change the knot type. Using an invariant of certain types of closed 3-braid diagrams, we show that if a closed 3-braid contains a nugatory crossing then its braid index is one or two. This proves a special case of a conjecture on nugatory crossings due to Xiao-Song Lin.

The Burau matrix and Fiedler's invariant for a closed braid

It is shown how Fiedler's `small state-sum' invariant for a braid can be calculated from the 2-variable Alexander polynomial of the link which consists of the closed braid together with the braid axis.

The Alexander polynomial for closed braids in lens spaces

We present a reduced Burau-like representation for the mixed braid group on one strand representing links in lens spaces and show how to calculate the Alexander polynomial of a link directly from the mixed braid.

5-move equivalence classes of links and their algebraic invariants

We start a systematic analysis of links up to 5-move equivalence. Our motivation is to develop tools which later can be used to study skein modules based on the skein relation being deformation of a 5-move (in an analogous way as the Kauffman skein module is a deformation of a 2-move, i.e. a crossing change). Our main tools are Jones and Kauffman polynomials and the fundamental group of the 2-fold branch cover of S^3 along a link. We use also the fact that a 5-move is a composition of two rational \pm (2,2)-moves (i.e. \pm 5/2-moves) and rational moves can be analyzed using the group of Fox co…

The Multivariable Alexander Polynomial for a Closed Braid

A simple multivariable version of the reduced Burau matrix is constructed for any braid. It is shown how the multivariable Alexander polynomial for the closure of the braid can be found directly from this matrix.

Diagrammatic representations of knots and links as closed braids

This is an expository article on diagrammatic representations of knots and links in various settings via braids.

On the skein module of the product of a surface and a circle

Let Sigma be a closed oriented surface of genus g. We show that the Kauffman bracket skein module of Sigma x S^1 over the field of rational functions in A has dimension at least 2^{2g+1}+2g-1.

伪链接的HOMFLYPT型不变量：通过Hecke代数中的解析

A HOMFLYPT-type invariant for pseudo links via a resolution in Hecke algebras

本文通过Hecke代数中的解析构造了伪链接的HOMFLYPT型不变量，解决了伪 Reidemeister 1 移动带来的障碍，基于解析同态和Ocneanu迹得到自然的伪 skein 关系。

Studying surfaces via closed braids

This is a review article on the Bennequin-Birman-Menasco machinery for studying embedded incompressible surfaces in 3-space via their `braid foliations'. Two cases are investigated: case (1) The surface has non-empty boundary; the boundary is a knot or link which is represented as a closed braid, Case (2) The surface is closed, but it lies in the complement of a knot or link which is represented as a closed braid. The main results in the area are established with full proofs, in a systematic fashion, with an eye toward making them accessible to the beginning reader. There are some new contribu…

One-cocycle invariants for closed braids

We introduce new polynomial isotopy invariants for closed braids. They are constructed as polynomial valued {\em Gauss diagram 1-cocycles} evaluated on the full rotation of the closed braid $\hat β$ around the core of the corresponding solid torus. They can be calculated with polynomial complexity with respect to the braid length and their derivatives evaluated at $x=1$ are finite type invariants of closed braids. Let the solid torus V be standardly embedded in the 3-sphere and let L be the core of the complementary solid torus $S^3\setminus V$. We give examples which show that a natural refin…

On a structure of random open books and closed braids

A result of Malyutin shows that a random walk on the mapping class group gives rise to an element whose fractional Dehn twist coefficient is large or small enough. We show that this leads to several properties of random 3-manifolds and links. For example, random closed braids and open books are hyperbolic.

On closed 3-braids with unknotting number one

We prove that if an alternating 3-braid knot has unknotting number one, then there must exist an unknotting crossing in any alternating diagram of it, and we enumerate such knots. The argument combines the obstruction to unknotting number one developed by Ozsváth and Szabó using Heegaard Floer homology, together with one coming from Donaldson's Theorem A.

On the kinkiness of closed braids

In this note, we prove a lower bound for the positive kinkiness of a closed braid which we then use to derive an estimate for the positive kinkiness of a link in terms of its Seifert system. As an application, we show that certain pretzel knots cannot be unknotted using only positive crossing changes. We also describe a subgroup of infinite rank in the smooth knot concordance group of which no element has a strongly quasipositive representative.

The Yang-Mills Measure in the Kauffman Bracket Skein Module

For each closed, orientable surface F, we construct a local, diffeomorphism invariant trace on the Kauffman bracket skein module K_t(F x [0,1]). The trace is defined when |t| is neither 0 nor 1, and at certain roots of unity. At t = - 1, the trace is integration against the symplectic measure on the SU(2) character variety of the fundamental group of F.

The HOMFLY Polynomial of Links in Closed Braid Form

It is well known that any link can be represented by the closure of a braid. The minimum number of strings needed in a braid whose closure represents a given link is called the braid index of the link and the well known Morton-Frank-Williams inequality reveals a close relationship between the HOMFLY polynomial of a link and its braid index. In the case that a link is already presented in a closed braid form, Jaeger derived a special formulation of the HOMFLY polynomial. In this paper, we prove a variant of Jaeger's result as well as a dual version of it. Unlike Jaeger's original reasoning, whi…

Algebraic functions and closed braids

This article was originally published in Topology 22 (1983). The present hyperTeXed redaction includes references to post-1983 results as Addenda, and corrects a few typographical errors. (See math.GT/0411115 for a more comprehensive overview of the subject as it appears 21 years later.)

The Khovanov width of twisted links and closed 3-braids

Khovanov homology is a bigraded Z-module that categorifies the Jones polynomial. The support of Khovanov homology lies on a finite number of slope two lines with respect to the bigrading. The Khovanov width is essentially the largest horizontal distance between two such lines. We show that it is possible to generate infinite families of links with the same Khovanov width from link diagrams satisfying certain conditions. Consequently, we compute the Khovanov width for all closed 3-braids.

Comparing Skein and Quantum Group Representations and Their Application to Asymptotic Faithfulness

We generalize the asymptotic faithfulness of the skein quantum $SU(2)$ representations of mapping class groups of orientable closed surfaces to skein $SU(3)$. Skein quantum representations of mapping class groups are different from the Reshetikin-Turaev ones from quantum groups or geometric quantization because they are given by different modular tensor categories. We conjecture asymptotic faithfulness holds for skein quantum $G$ representations when $G$ is a simply-connected simple Lie group. The difficulty for such a generalization lies in the lack of an explicit description of the fusion sp…

Homogeneous links and closed homogeneous braids

Is any positive knot the closure of a positive braid? No. But if we consider positivity in terms of the generators of the braid group due to Birman, Ko and Lee, then the answer is yes. In this paper we prove that the same occurs when considering homogeneity. In the way we prove that the plumbing of two surfaces is a BKL-homogeneous surface if and only if both summands are BKL-homogeneous surfaces, a parallel result to that of Rudolph involving quasipositive surfaces. BKL-homogeneous surfaces are, in fact, a natural generalization of quasipositive surfaces.

A non-degenerate exchange move always produces infinitely many non-conjugate braids

We show that if a link $L$ has a closed $n$-braid representative admitting non-degenerate exchange move, an exchange move that does not obviously preserve the conjugacy class, $L$ has infinitely many non-conjugate closed $n$-braid representatives.

Invariants of closed braids via counting surfaces

A Gauss diagram is a simple, combinatorial way to present a link. It is known that any Vassiliev invariant may be obtained from a Gauss diagram formula that involves counting subdiagrams of certain combinatorial types. In this paper we present simple formulas for an infinite family of invariants in terms of counting surfaces of a certain genus and number of boundary components in a Gauss diagram associated with a closed braid. We then identify the resulting invariants with partial derivatives of the HOMFLY-PT polynomial.

小3-流形的Kauffman括号skein模

Kauffman bracket skein modules of small 3-manifolds

本文开发了一种计算闭3-流形Kauffman括号skein模的新方法，证明了在驯顺和既约条件下其维数等于特征簇闭点数，并首次实现了对闭双曲3-流形skein模的计算。

Meridian twisting of closed braids and the Homfly polynomial

Let $β$ be a braid on $n$ strands, with exponent sum $w$. Let $Δ$ be the Garside half-twist braid. We prove that the coefficient of $v^{w-n+1}$ in the Homfly polynomial of the closure of $β$ agrees with $(-1)^{n-1}$ times the coefficient of $v^{w+n^2-1}$ in the Homfly polynomial of the closure of $βΔ^2$. This coincidence implies that the lower Morton--Franks-Williams estimate for the $v$--degree of the Homfly polynomial of $\hatβ$ is sharp if and only if the upper MFW estimate is sharp for the $v$--degree of the Homfly polynomial of $\hat{βΔ^2}$.