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Related papers: Link invariants from finite biracks

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We describe a way of representing finite biquandles with n elements as 2n x 2n block matrices. Any finite biquandle defines an invariant of virtual knots through counting homomorphisms. The counting invariants of non-quandle biquandles can…

Geometric Topology · Mathematics 2007-05-23 Sam Nelson , John Vo

We revisit finite racks and quandles using a perspective based on permutations which can aid in the understanding of the structure. As a consequence we recover old results and prove new ones. We also present and analyze several examples.

Geometric Topology · Mathematics 2007-05-23 Pedro Lopes , Dennis Roseman

Recently, Bigelow defined a diagrammatic method for calculating the Alexander polynomial of a knot or link by resolving crossings in a planar algebra. I will present my multivariate version of Bigelow's calculation. The advantage to my…

Geometric Topology · Mathematics 2015-03-20 K. Grace Kennedy

We show that the lower bounds for Betti numbers given in math.GT/9909161 are equalities for a class of racks that includes dihedral and Alexander racks. We confirm a conjecture from the same paper by defining a splitting for the short exact…

Geometric Topology · Mathematics 2007-05-23 R. A. Litherland , Sam Nelson

We introduce the notion of N-reduced dynamical cocycles and use these objects to define enhancements of the rack counting invariant for classical and virtual knots and links. We provide examples to show that the new invariants are not…

Geometric Topology · Mathematics 2011-08-23 Alissa S. Crans , Sam Nelson , Aparna Sarkar

In this article, we introduce rack invariants of oriented Legendrian knots in the 3-dimensional Euclidean space endowed with the standard contact structure, which we call Legendrian racks. These invariants form a generalization of the…

Geometric Topology · Mathematics 2017-07-04 Dheeraj Kulkarni , T. V. H. Prathamesh

We introduce an infinite family of quiver representation-valued invariants of classical, virtual and surface-knots and links associated to a choice of finite biquandle, commutative unital ring, biquandle module and set of biquandle…

Geometric Topology · Mathematics 2025-11-04 Yewon Joung , Sam Nelson

In our previous papers we introduced categorical invariants, which are, roughly speaking, sets of triangulated subcategories in a given triangulated category and their quotients. Here is extended the list of examples, where these sets are…

Category Theory · Mathematics 2019-07-31 George Dimitrov , Ludmil Katzarkov

We enhance the biquandle counting invariant using elements of truncated biquandle-labeled Polyak algebras. These finite type enhancements reduce to the finite type enhancements defined by Goussarov, Polyak and Viro for the trivial biquandle…

Geometric Topology · Mathematics 2015-06-03 Sam Nelson

We study the distribution of arithmetic invariants associated to Alexander polynomials for certain infinite families of links. The families of links we consider arise from braids on a fixed number of strings. We explore analogies with…

Geometric Topology · Mathematics 2023-07-27 Anwesh Ray

We introduce a new family of invariants of oriented classical and virtual knots and links using fares, maps from paths in biquandle-colored diagrams to an abelian coefficient group. We consider the cases of 1-fares and 2-fares, provide…

Geometric Topology · Mathematics 2026-02-09 Sam Nelson , Stella Shah

Racks and quandles are algebraic structures with a single binary operation that is right self-distributive and right invertible, and additionally idempotent in the case of quandles. The invertibility condition is equivalent to the existence…

Rings and Algebras · Mathematics 2024-07-23 Wayne Burrows , Christopher Tuffley

A biquandle is a solution to the set-theoretical Yang-Baxter equation, which yields invariants for virtual knots such as the coloring number and the state-sum invariant. A virtual biquandle enriches the structure of a biquandle by…

Geometric Topology · Mathematics 2025-09-10 Mohamed Elhamdadi , Manpreet Singh

The combinatorial approach to knot theory treats knots as diagrams modulo Reidemeister moves. Many constructions of knot invariants (e.g., index polynomials, quandle colorings, etc.) use elements of diagrams such as arcs and crossings by…

Geometric Topology · Mathematics 2025-04-29 Igor Nikonov

We publish a table of primitive finite-type invariants of order less than or equal to six, for knots of ten or fewer crossings. We note certain mod-2 congruences, one of which leads to a chirality criterion in the Alexander polynomial. We…

Geometric Topology · Mathematics 2007-05-23 Ted Stanford

We define a family of generalizations of the two-variable quandle polynomial. These polynomial invariants generalize in a natural way to eight-variable polynomial invariants of finite biquandles. We use these polynomials to define a family…

Quantum Algebra · Mathematics 2019-08-15 Sam Nelson

A rack shadow is a set X with a rack action by a rack R, analogous to a vector space over a field. We use shadow colorings of classical link diagrams to define enhanced rack counting invariants and show that the enhanced invariants are…

Geometric Topology · Mathematics 2010-07-14 Wesley Chang , Sam Nelson

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

Multi-virtual knot theory was introduced in $2024$ by the first author. In this paper, we initiate the study of algebraic invariants of multi-virtual links. After determining a generating set of (oriented) multi-virtual Reidemeister moves,…

Geometric Topology · Mathematics 2025-04-15 Louis H. Kauffman , Sujoy Mukherjee , Petr Vojtěchovský

We introduce and investigate a natural family of metrics on connected components of a rack. The metrics are closely related to certain bi-invariant metrics on the group of inner automorphisms of the rack. We also introduce a bounded…

Group Theory · Mathematics 2024-06-13 Jarek Kędra