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Related papers: Virtual shadow modules and their link invariants

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Using general principles of the theory of vertex operator algebras and their twisted modules, we obtain a bosonic, twisted construction of a certain central extension of a Lie algebra of differential operators on the circle, for an…

Quantum Algebra · Mathematics 2007-05-23 Benjamin Doyon , James Lepowsky , Antun Milas

In this paper, we use skein-theoretic techniques to classify all virtual knot polynomials and trivalent graph invariants with certain smallness conditions. The first half of the paper classifies all virtual knot polynomials giving…

Quantum Algebra · Mathematics 2020-08-11 Joshua R. Edge

This paper extends the construction of invariants for virtual knots to virtual long knots and introduces two new invariant modules of virtual long knots. Several interesting features are described that distinguish virtual long knots from…

Geometric Topology · Mathematics 2007-06-01 Andrew Bartholomew , Roger Fenn , Naoko Kamada , Seiichi Kamada

The purpose of this paper is to generalize Zhu's theorem about characters of modules over a vertex operator algebra graded by integer conformal weights, to the setting of a vertex operator superalgebra graded by rational conformal weights.…

Representation Theory · Mathematics 2013-07-19 Jethro van Ekeren

We extend the Yang-Baxter cocycle invariants for virtual knots by augmenting Yang-Baxter 2-cocycles with cocycles from a cohomology theory associated to a virtual biquandle structure. These invariants coincide with the classical Yang-Baxter…

Geometric Topology · Mathematics 2008-02-22 Jose Ceniceros , Sam Nelson

We generalize unoriented handlebody-links to the twisted virtual case, obtaining Reidemeister moves for handlebody-links in ambient spaces of the form $\Sigma\times [0,1]$ for $\Sigma$ a compact closed 2-manifold up to stable equivalence.…

Geometric Topology · Mathematics 2017-11-15 Sam Nelson , Yuqi Zhao

We study novel invariants of modular categories that are beyond the modular data, with an eye towards a simple set of complete invariants for modular categories. Our focus is on the $W$-matrix--the quantum invariant of a colored framed…

Quantum Algebra · Mathematics 2018-07-02 Parsa Bonderson , Colleen Delaney , César Galindo , Eric C. Rowell , Alan Tran , Zhenghan Wang

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

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

We introduce a new infinite family of enhancements of the biquandle homset invariant called biquandle arrow weights. These invariants assign weights in an abelian group to intersections of arrows in a Gauss diagram representing a classical…

Geometric Topology · Mathematics 2023-04-18 Sam Nelson , Migiwa Sakurai

Biracks are algebraic structures related to knots and links. We define a new enhancement of the birack counting invariant for oriented classical and virtual knots and links via algebraic structures called birack dynamical cocycles. The new…

Geometric Topology · Mathematics 2012-05-22 Sam Nelson , Emily Watterberg

From the braid-valued Burau module over the braid group we construct the Yang-Baxter matrices yielding the Alexander- and the Jones knot invariants. This generalises an observation of V. F. R. Jones.

q-alg · Mathematics 2008-02-03 Florin Constantinescu , Mirko Luedde

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

The Alexander biquandle of a virtual knot or link is a module over a 2-variable Laurent polynomial ring which is an invariant of virtual knots and links. The elementary ideals of this module are then invariants of virtual isotopy which…

Geometric Topology · Mathematics 2013-09-30 Alissa S. Crans , Allison Henrich , Sam Nelson

It is an open question whether there are Vassiliev invariants that can distinguish an oriented knot from its inverse, i.e., the knot with the opposite orientation. In this article, an example is given for a first order Vassiliev invariant…

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

Let k be a commutative ring. We find and characterize a new family of twisted planes (i. e. associative unitary k-algebra structures on the k-module k[X,Y], having k[X] and and k[Y] as subalgebras).Similar results are obtained for the…

Rings and Algebras · Mathematics 2007-12-27 Jorge A. Guccione , Juan J. Guccione , Christian Valqui

Drinfeld twists, and the twists of Giaquinto and Zhang, allow for algebras and their modules to be deformed by a cocycle. We prove general results about cocycle twists of algebra factorisations and induced representations and apply them to…

Quantum Algebra · Mathematics 2025-01-14 Yuri Bazlov , Edward Jones-Healey

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

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 define new notions of groups of virtual and welded knots (or links) and we study their relations with other invariants, in particular the Kauffman group of a virtual knot.

Geometric Topology · Mathematics 2012-04-17 Valeriy G. Bardakov , Paolo Bellingeri