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We study rack polynomials and the link invariants they define. We show that constant action racks are classified by their generalized rack polynomials and show that $ns^at^a$-quandles are not classified by their generalized quandle…

Geometric Topology · Mathematics 2019-03-13 Tim Carrell , Sam Nelson

Starting from considering deeper relationship between conjugacy classes and irreducible representations of a finite group $G$, we find some quite simple $R-$matrice defined by using finite groups. This construction produces many sets (or…

Geometric Topology · Mathematics 2018-09-25 Zhi Chen

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 new algebraic structure called Legendrian racks or racks with Legendrian structure, motivated by the front-projection Reidemeister moves for Legendrian knots. We provide examples of Legendrian racks and use these algebraic…

Geometric Topology · Mathematics 2021-01-26 Jose Ceniceros , Mohamed Elhamdadi , Sam Nelson

Quandle cocycles are constructed from extensions of quandles. The theory is parallel to that of group cohomology and group extensions. An interpretation of quandle cocycle invariants as obstructions to extending knot colorings is given, and…

Geometric Topology · Mathematics 2007-05-23 J. Scott Carter , Mohamed Elhamdadi , Marina Appiou Nikiforou , Masahico Saito

We introduce \textit{Kaestner brackets}, a generalization of biquandle brackets to the case of parity biquandles. This infinite set of quantum enhancements of the biquandle counting invariant for oriented virtual knots and links includes…

Geometric Topology · Mathematics 2020-06-12 Forest Kobayashi , Sam Nelson

A polynomial is presented that models a topological knot in a unique manner. It distinguishes all types of knots including the orientation and has a group theory interpretation. The topologies may be labeled via a number, which upon a base…

General Physics · Physics 2007-05-23 Gordon Chalmers

A rack of order $n$ is a binary operation $\rack$ on a set $X$ of cardinality $n$, such that right multiplication is an automorphism. More precisely, $(X,\rack)$ is a rack provided that the map $x\mapsto x\rack y$ is a bijection for all…

Geometric Topology · Mathematics 2012-03-30 Simon R. Blackburn

In this study of the Reidemeister moves within the classical knot theory, we focus on hard diagrams of knots and links, categorizing them as either rigid or shaky based on their adaptability to certain moves. We establish that every link…

Geometric Topology · Mathematics 2025-10-14 Michal Jablonowski

We introduce and study so-called self-indexed graphs. These are (oriented) finite graphs endowed with a map from the set of edges to the set of vertices. Such graphs naturally arise from classical knot and link diagrams. In fact, the graphs…

Geometric Topology · Mathematics 2007-05-23 Matias Graña , Vladimir Turaev

Let $X$ be a differentiable manifold endowed with a transitive action $\alpha:A\times X\longrightarrow X$ of a Lie group $A$. Let $K$ be a Lie group. Under suitable technical assumptions, we give explicit classification theorems, in terms…

Differential Geometry · Mathematics 2013-11-19 Indranil Biswas , Andrei Teleman

Tied links and the tied braid monoid were introduced recently by the authors and used to define new invariants for classical links. Here, we give a version purely algebraic-combinatoric of tied links. With this new version we prove that the…

Geometric Topology · Mathematics 2021-01-28 Francesca Aicardi , Jesus Juyumaya

Given any unoriented link diagram, a group of new knot invariants are constructed. Each of them satisfies a generalized 4 term skein relation. The coefficients of each invariant is from a commutative ring. Homomorphisms and representations…

Geometric Topology · Mathematics 2010-04-14 Zhiqing Yang , Jifu Xiao

The theory of welded and extended welded knots is a generalization of classical knot theory. Welded (resp. extended welded) knot diagrams include virtual crossings (resp. virtual crossings and wen marks) and are equivalent under an extended…

Geometric Topology · Mathematics 2018-09-18 N. Backes , M. Kaiser , T. Leafblad , E. I. C. Peterson , D. N. Yetter

We describe various properties and give several characterizations of ternary groups satisfying two axioms derived from the third Reidemeister move in knot theory. Using special attributes of such ternary groups, such as semi-commutativity,…

Group Theory · Mathematics 2019-10-29 Maciej Niebrzydowski , Agata Pilitowska , Anna Zamojska-Dzienio

This article lays the foundations for an analogue of geometric group theory that studies actions on graphs by right quasigroups, including racks and quandles. We study markings of graphs that realize racks, and we introduce (di)graph…

Geometric Topology · Mathematics 2026-04-01 Luc Ta

The theory of rack and quandle modules is developed - in particular a tensor product is defined, and shown to satisfy an appropriate adjointness condition. Notions of free rack and quandle modules are introduced, and used to define an…

Category Theory · Mathematics 2007-05-23 Nicholas Jackson

We show that some ternary quasigroups appear naturally as invariants of classical links and links on surfaces. We also note how to obtain from them invariants of Yoshikawa moves. In our previous paper, we defined homology theory for…

Geometric Topology · Mathematics 2018-05-16 Maciej Niebrzydowski

In this paper we introduce a representation of knots and links called a cube diagram. We show that a property of a cube diagram is a link invariant if and only if the property is invariant under two types of cube diagram operations. A knot…

Geometric Topology · Mathematics 2012-05-24 Scott Baldridge , Adam Lowrance

We show that the cohomology groups usually associated with racks and quandles agree with the Quillen cohomology groups for the algebraic theories of racks and quandles, respectively. We also explain how this makes available the entire range…

Algebraic Topology · Mathematics 2019-02-04 Markus Szymik