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Related papers: Non-classicality and quandle difference invariants

200 papers

We study the quandle counting invariant for a certain family of finite quandles with trivial orbit subquandles. We show how these invariants determine the linking number of classical two-component links up to sign.

Geometric Topology · Mathematics 2008-08-13 Natasha Harrell , Sam Nelson

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 will strengthen the known upper and lower bounds on the delta-crossing number of knots in therms of the triple-crossing number. The latter bound turns out to be strong enough to obtain (unknown values of) triple-crossing numbers for a…

Geometric Topology · Mathematics 2023-03-06 Michal Jablonowski

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

The fundamental quandle is a complete invariant for unoriented tame knots \cite{JO, Ma} and non-split links \cite{FR}. The proof involves proving a relationship between the components of the fundamental quandle and the cosets of the…

Geometric Topology · Mathematics 2026-02-26 Blake Mellor

In 2002, D. Hrencecin and L.H. Kauffman defined a filamentation invariant on oriented chord diagrams that may determine whether the corresponding flat virtual knot diagrams are non-trivial. A virtual knot diagram is non-classical if its…

Geometric Topology · Mathematics 2007-05-23 William J. Schellhorn

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

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

We define ambient isotopy invariants of oriented knots and links using the counting invariants of framed links defined by finite racks. These invariants reduce to the usual quandle counting invariant when the rack in question is a quandle.…

Geometric Topology · Mathematics 2013-07-30 Sam Nelson

In this paper we give the results of a computer search for biracks of small size and we give various interpretations of these findings. The list includes biquandles, racks and quandles together with new invariants of welded knots and…

Geometric Topology · Mathematics 2010-01-29 Andrew Bartholomew , Roger Fenn

We use idempotents in quandle rings in combination with the state sum invariants of knots to distinguish all of the 12965 prime oriented knots up to 13 crossings using only 21 connected quandles and three quandles made of idempotents in…

Geometric Topology · Mathematics 2024-07-01 Mohamed Elhamdadi , Dipali Swain

The homology and cohomology of quandles and racks are used in knot theory: given a finite quandle and a cocycle, we can construct a knot invariant. This is a quick introductory survey to the invariants of knots derived from quandles and…

Geometric Topology · Mathematics 2007-05-23 Seiichi Kamada

While knotoids on the sphere are well-understood by a variety of invariants, knotoids on the plane have proven more subtle to classify due to their multitude over knotoids on the sphere and a lack of invariants that detect a diagram's…

Geometric Topology · Mathematics 2024-07-11 Mohamed Elhamdadi , Wout Moltmaker , Masahico Saito

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 define an invariant of welded virtual knots from each finite crossed module by considering crossed module invariants of ribbon knotted surfaces which are naturally associated with them. We elucidate that the invariants obtained are non…

Geometric Topology · Mathematics 2017-05-23 Louis H. Kauffman , João Faria Martins

Three new knot invariants are defined using cocycles of the generalized quandle homology theory that was proposed by Andruskiewitsch and Gra\~na. We specialize that theory to the case when there is a group action on the coefficients. First,…

Geometric Topology · Mathematics 2007-05-23 J. Scott Carter , Mohamed Elhamdadi , Matias Graña , Masahico Saito

We introduce three kinds of invariants of a virtual knot called the first, second, and third intersection polynomials. The definition is based on the intersection number of a pair of curves on a closed surface. The calculations of…

Geometric Topology · Mathematics 2022-01-26 Ryuji Higa , Takuji Nakamura , Yasutaka Nakanishi , Shin Satoh

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

Joyce has shown that the fundamental quandle of a classical knot can be derived from consideration of the fundamental group and the peripheral structure of the knot, and also that the group and much of the peripheral structure can be…

Geometric Topology · Mathematics 2009-05-26 Blake Winter

In this paper we give the results of a computer search for biracks of small size and we give various interpretations of these findings. The list includes biquandles, racks and quandles together with new invariants of welded knots and…

Geometric Topology · Mathematics 2010-04-09 Andrew Bartholomew , Roger Fenn