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Related papers: Singquandle Shadows and Singular knot Invariants

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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

In this short survey we review recent results dealing with algebraic structures (quandles, psyquandles, and singquandles) related to singular knot theory. We first explore the singquandles counting invariant and then consider several recent…

Geometric Topology · Mathematics 2021-03-10 Jose Ceniceros , Indu R. Churchill , Mohamed Elhamdadi , Mustafa Hajij

We enhance the psyquandle counting invariant for singular knots and pseudoknots using quivers analogously to quandle coloring quivers. This enables us to extend the in-degree polynomial invariants from quandle coloring quiver theory to the…

Geometric Topology · Mathematics 2021-07-14 Jose Ceniceros , Anthony Christiana , Sam Nelson

We extend the quandle cocycle invariant to oriented singular knots and links using algebraic structures called \emph{oriented singquandles} and assigning weight functions at both regular and singular crossings. This invariant coincides with…

Geometric Topology · Mathematics 2021-03-02 Jose Ceniceros , Indu R. Churchill , Mohamed Elhamdadi , Mustafa Hajij

Quandle cocycle invariants form a powerful and well developed tool in knot theory. This paper treats their variations - namely, positive and twisted quandle cocycle invariants, and shadow invariants. We interpret the former as particular…

Geometric Topology · Mathematics 2014-10-07 Seiichi Kamada , Victoria Lebed , Kokoro Tanaka

We introduce a new invariant for a $2$-knot in $S^4$, called the shadow-complexity, based on the theory of Turaev shadows, and we give a characterization of $2$-knots with shadow-complexity at most $1$. Specifically, we show that the unknot…

Geometric Topology · Mathematics 2024-12-25 Hironobu Naoe

We construct elements of the third quandle homology groups of knot quandles, which are called the shadow fundamental classes. They play the same roles for the shadow quandle cocycle invariants of knots as the fundamental classes of knot…

Geometric Topology · Mathematics 2009-06-04 Yasto Kimura

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

The aim of this paper is to define certain algebraic structures coming from generalized Reidemeister moves of singular knot theory. We give examples, show that the set of colorings by these algebraic structures is an invariant of singular…

Geometric Topology · Mathematics 2018-06-21 Indu R. U. Churchill , M. Elhamdadi , M. Hajij , Sam Nelson

We extend the notion of biquandle brackets to the case of psyquandles, defining quantum enhancements of the psyquandle counting invariant for singular knots and pseudoknots. We provide examples to illustrate the computation of these…

Geometric Topology · Mathematics 2025-08-20 Sam Nelson , Natsumi Oyamaguchi

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

The notion of a pseudoknot is defined as an equivalence class of knot diagrams that may be missing some crossing information. We provide here a topological invariant schema for pseudoknots and their relatives, 4-valent rigid vertex spatial…

Geometric Topology · Mathematics 2016-03-15 Allison Henrich , Louis H. Kauffman

We introduce a new class of quantum enhancements we call biquandle brackets, which are customized skein invariants for biquandle colored links.Quantum enhancements of biquandle counting invariants form a class of knot and link invariants…

Geometric Topology · Mathematics 2017-02-17 Sam Nelson , Michael E. Orrison , Veronica Rivera

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

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

This paper studies the chirality of knotoids using shadow quandle colorings and the shadow quandle cocycle invariant. The shadow coloring number and the shadow quandle cocycle invariant is shown to distinguish infinitely many knotoids from…

Geometric Topology · Mathematics 2022-07-08 Nicholas Cazet

In this paper we deal with the notion of singquandles introduced in Indu R. U. Churchill, Mohamed Elhamdadi, Mustafa Hajij, and Sam Nelson, Singular knots and involutive quandles, Journal of Knot Theory and Its Ramifications 26 (2017), no.…

Geometric Topology · Mathematics 2021-07-13 Marco Bonatto , Alessia Cattabriga

We introduce and investigate dichromatic singular links. We also construct G-Family of singquandles and use them to define counting invariants for unoriented dichromatic singular links. We provide some examples to show that these invariants…

Geometric Topology · Mathematics 2023-01-11 Mohd Ibrahim Sheikh , Mohamed Elhamdadi , Danish Ali

We define new invariants of knots by means of quandle colorings and longitudinal information. These invariants can be applied to a tangle embedding problem and recognizing non-classical virtual knots.

Geometric Topology · Mathematics 2019-10-29 Maciej Niebrzydowski

We bring cocycle enhancement theory to the case of psyquandles. Analogously to our previous work on virtual biquandle cocycle enhancements, we define enhancements of the psyquandle counting invariant via pairs of a biquandle 2-cocycle and a…

Geometric Topology · Mathematics 2020-10-01 Jose Ceniceros , Sam Nelson
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