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We define and study a bigraded knot invariant whose Euler characteristic is the Alexander polynomial, closely connected to knot Floer homology. The invariant is the homology of a chain complex whose generators correspond to Kauffman states…

Geometric Topology · Mathematics 2018-02-06 Peter Ozsvath , Zoltan Szabo

The homology and cohomology of quandles and racks are used in knot theory: given a finite quandle and a cocycle, we can construct a knot invariant. This is a quick introductory survey to the invariants of knots derived from quandles and…

Geometric Topology · Mathematics 2007-05-23 Seiichi Kamada

Virtual knot theory is a generalization of knot theory which is based on Gauss chord diagrams and link diagrams on closed oriented surfaces. A twisted knot is a generalization of a virtual knot, which corresponds to a link diagram on a…

Geometric Topology · Mathematics 2015-12-04 Naoko Kamada

A perturbative expansion of knot invariants is derived using quantum cluster algebras. By interpreting the $R$-matrix of $U_q(\mathfrak{sl}_2)$ as a cluster transformation and introducing an auxiliary parameter $\epsilon$, we derive a…

Geometric Topology · Mathematics 2026-05-21 Boudewijn Bosch

In this note we give concise formulas, which lead to a simple and fast computer program that computes a powerful knot invariant. This invariant $\rho_1$ is not new, yet our formulas are by far the simplest and fastest: given a knot we write…

Geometric Topology · Mathematics 2024-04-16 Dror Bar-Natan , Roland van der Veen

We construct knot invariants from the radical part of projective modules of restricted quantum groups. We also show a relation between these invariants and the colored Alexander invariants.

Geometric Topology · Mathematics 2010-06-01 Jun Murakami , Kiyokazu Nagatomo

In this paper we define and give examples of a family of polynomial invariants of virtual knots and links. They arise by considering certain 2$\times$2 matrices with entries in a possibly non-commutative ring, for example the quaternions.…

Geometric Topology · Mathematics 2007-05-23 Andrew Bartholomew , Roger Fenn

We introduce two new families of polynomial invariants of oriented classical and virtual knots and links defined as decategorfications of the quandle coloring quiver. We provide examples to illustrate the computation of the invariants, show…

Geometric Topology · Mathematics 2025-08-18 Anusha Kabra , Sam Nelson

Defined by Joyce and Matveev, the fundamental quandle is a complete invariant of oriented classical knots. We consider invariants of knots defined from quotients of the fundamental quandle. In particular, we introduce the fundamental Latin…

Geometric Topology · Mathematics 2014-04-25 Sam Nelson , Sherilyn Tamagawa

Given a virtual knot $K$, we construct a group $VG_K$ called the virtual knot group, and we use the elementary ideals of $VG_K$ to define invariants of $K$ called the virtual Alexander invariants. For instance, associated to the $k=0$ ideal…

Geometric Topology · Mathematics 2015-05-07 Hans U. Boden , Emily Dies , Anne Isabel Gaudreau , Adam Gerlings , Eric Harper , Andrew J. Nicas

We explore a knot invariant derived from colorings of corresponding $1$-tangles with arbitrary connected quandles. When the quandle is an abelian extension of a certain type the invariant is equivalent to the quandle $2$-cocycle invariant.…

Geometric Topology · Mathematics 2016-08-09 W. Edwin Clark , Larry A. Dunning , Masahico Saito

A polynomial invariant of virtual links, arising from an invariant of links in thickened surfaces introduced by Jaeger, Kauffman, and Saleur, is defined and its properties are investigated. Examples are given that the invariant can detect…

Geometric Topology · Mathematics 2007-05-23 J. Sawollek

We extend knot contact homology to a theory over the ring $\mathbb{Z}[\lambda^{\pm 1},\mu^{\pm 1}]$, with the invariant given topologically and combinatorially. The improved invariant, which is defined for framed knots in $S^3$ and can be…

Geometric Topology · Mathematics 2008-06-11 Lenhard Ng

This paper describes a polynomial invariant of virtual knots that is defined in terms of an integer labeling of the virtual knot diagram. This labeling is seen to derive from an essentially unique structure of affine flat biquandle for flat…

Algebraic Topology · Mathematics 2014-07-25 Louis H. Kauffman

One construction of the Alexander polynomial is as a quantum invariant associated with representations of restricted quantum $\mathfrak{sl}_2$ at a fourth root of unity. We generalize this construction to define a link invariant…

Quantum Algebra · Mathematics 2026-03-19 Matthew Harper

Construction of representations of braid group generators from $N$-state vertex models provide an elegant route to study knot and link invariants. Using such a braid group representation, an algebraic formula for the link invariants was put…

High Energy Physics - Theory · Physics 2019-01-11 Saswati Dhara , Romesh K. Kaul , P. Ramadevi , Vivek Kumar Singh

We enhance the quandle counting invariants of oriented classical and virtual knots and links using a construction similar to quandle modules but inspired by symplectic quandle operations rather than Alexander quandle operations. Given a…

Geometric Topology · Mathematics 2023-04-18 Will Gilroy , Sam Nelson

We consider an algebra of (classical or virtual) tangles over an ordered circuit operad and introduce Conway-type invariants of tangles which respect this algebraic structure. The resulting invariants contain both the coefficients of the…

Geometric Topology · Mathematics 2010-11-30 Michael Polyak

We consider a quiver structure on the set of quandle colorings of an oriented knot or link diagram. This structure contains a wealth of knot and link invariants and provides a categorification of the quandle counting invariant in the most…

Geometric Topology · Mathematics 2018-10-09 Karina Cho , Sam Nelson

We define a two-variable polynomial invariant of finite quandles. In many cases this invariant completely determines the algebraic structure of the quandle up to isomorphism. We use this polynomial to define a family of link invariants…

Quantum Algebra · Mathematics 2008-08-13 Sam Nelson