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Related papers: Biquandle Bracket Quivers

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It is known that the number of biquandle colorings of a long virtual knot diagram, with a fixed color of the initial arc, is a knot invariant. In this paper we describe a more subtle invariant: a family of biquandle endomorphisms obtained…

Geometric Topology · Mathematics 2019-10-29 Maciej Niebrzydowski

We define a family of quiver representation-valued invariants of oriented classical and virtual knots and links associated to a choice of finite quandle $X$, abelian group $A$, set of quandle 2-cocycles $C\subset H^2_Q(x;A)$, choice of…

Geometric Topology · Mathematics 2024-12-24 Sam Nelson

Quandle Coloring Quivers are directed graph-valued invariants of classical and virtual knots and links associated to finite quandles. Quandle action quivers are subquivers of the full quandle coloring quiver associated to quandle actions by…

Geometric Topology · Mathematics 2024-04-02 Mason Cai , Sam Nelson

In this paper, we introduce invariants of virtual knotoids based on biquandles and biquandle virtual brackets. We show that one of these invariants, namely biquandle virtual bracket matrix, is a proper enhancement of the other invariants…

Algebraic Topology · Mathematics 2025-07-11 Neslihan Gügümcü , Hamdi Kayaslan

We use the structure of skew braces to enhance the biquandle counting invariant for virtual knots and links for finite biquandles defined from skew braces. We introduce two new invariants: a single-variable polynomial using skew brace…

Geometric Topology · Mathematics 2022-06-30 Melody Chang , Sam Nelson

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

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

We define counting and cocycle enhancement invariants of virtual knots using parity biquandles. These invariants are determined by pairs consisting of a biquandle 2-cocycle \phi^0 and a map \phi^1 with certain compatibility conditions…

Geometric Topology · Mathematics 2016-06-16 Aaron Kaestner , Sam Nelson , Leo Selker

We investigate connections between biquandle colorings, quiver enhancements, and several notions of the bridge numbers $b_i(K)$ for virtual links, where $i=1,2$. We show that for any positive integers $m \leq n$, there exists a virtual link…

Geometric Topology · Mathematics 2025-04-15 Tirasan Khandhawit , Puttipong Pongtanapaisan , Brandon Wang

In [14], the second named author constructed the bracket invariant [.] of virtual knots valued in pictures (linear combinations of virtual knot diagrams with some crossing information omitted), such that for many diagrams K, the following…

Geometric Topology · Mathematics 2017-01-24 Denis P. Ilyutko , Vassily O. Manturov

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

We enhance the quandle coloring quiver invariant of oriented knots and links with quandle modules. This results in a two-variable polynomial invariant with specializes to the previous quandle module polynomial invariant as well as to the…

Geometric Topology · Mathematics 2020-11-12 Karma Istanbouli , Sam Nelson

Coloring numbers are one of the simplest combinatorial invariants of knots and links to describe. And with Joyce's introduction of quandles, we can understand them more algebraically. But can we extend these invariants to tangles -- knots…

Geometric Topology · Mathematics 2008-03-12 John Armstrong

We identify a subcategory of biracks which define counting invariants of unoriented links, which we call involutory biracks. In particular, involutory biracks of birack rank N=1 are biquandles, which we call bikei. We define counting…

Geometric Topology · Mathematics 2011-04-25 Sinan Aksoy , Sam Nelson

In this short survey article we collect the current state of the art in the nascent field of \textit{quantum enhancements}, a type of knot invariant defined by collecting values of quantum invariants of knots with colorings by various…

Geometric Topology · Mathematics 2026-02-19 Sam Nelson

We generalize the notion of biquandles to psyquandles and use these to define invariants of oriented singular links and pseudolinks. In addition to psyquandle counting invariants, we introduce Alexander psyquandles and corresponding…

Geometric Topology · Mathematics 2017-10-25 Sam Nelson , Natsumi Oyamaguchi , Radmila Sazdanovic

We generalize the notion of the quandle polynomial to the case of singquandles. We show that the singquandle polynomial is an invariant of finite singquandles. We also construct a singular link invariant from the singquandle polynomial and…

Geometric Topology · Mathematics 2021-01-21 Jose Ceniceros , Indu R. Churchill , Mohamed Elhamdadi

We incorporate quandle cocycle information into the quandle coloring quivers we defined in arXiv:1807.10465 to define weighted directed graph-valued invariants of oriented links we call \textit{quandle cocycle quivers}. This construction…

Geometric Topology · Mathematics 2019-04-22 Karina Cho , Sam Nelson

A group-theoretical method, via Wada's representations, is presented to distinguish Kishino's virtual knot from the unknot. Biquandles are constructed for any group using Wada's braid group representations. Cocycle invariants for these…

Geometric Topology · Mathematics 2007-05-23 J. Scott Carter , Mohamed Elhamdadi , Masahico Saito , Daniel S. Silver , Susan G. Williams

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