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We develop the study of the twelve intersection polynomials of long virtual knots, previously introduced in our preceding paper. We define two geometric invariants, the $1$- and $2$-supporting genera, using two distinct surface…

Geometric Topology · Mathematics 2025-12-08 Takuji Nakamura , Yasutaka Nakanishi , Shin Satoh , Kodai Wada

We introduce an invariant of alternating knots and links (called here WRP), namely a pair of integer polynomials associated with their two checkerboard planar graphs from their minimal diagram. We prove that the invariant is well-defined…

Geometric Topology · Mathematics 2025-05-27 Michal Jablonowski

In this paper, we define some polynomial invariants for virtual knots and links. In the first part we use Manturov's parity axioms to obtain a new polynomial invariant of virtual knots. This invariant can be regarded as a generalization of…

Geometric Topology · Mathematics 2013-12-31 Zhiyun Cheng , Hongzhu Gao

We prove a Kauffman-Murasugi-Thistlethwaite theorem for alternating links in thickened surfaces. It states that any reduced alternating diagram of a link in a thickened surface has minimal crossing number, and any two reduced alternating…

Geometric Topology · Mathematics 2022-09-22 Hans U. Boden , Homayun Karimi

We give a new interpretation of the Alexander polynomial $\Delta_0$ for virtual knots due to Sawollek and Silver and Williams, and use it to show that, for any virtual knot, $\Delta_0$ determines the writhe polynomial of Cheng and Gao…

Geometric Topology · Mathematics 2018-08-14 Blake Mellor

We consider several classes of knotted objects, namely usual, virtual and welded pure braids and string links, and two equivalence relations on those objects, induced by either self-crossing changes or self-virtualizations. We provide a…

Geometric Topology · Mathematics 2017-11-30 Benjamin Audoux , Paolo Bellingeri , Jean-Baptiste Meilhan , Emmanuel Wagner

The aim of this paper is to introduce a polynomial invariant $f_K(t)$ for virtual knots. We show that $f_K(t)$ can be used to distinguish some virtual knot from its inverse and mirror image. The behavior of $f_K(t)$ under connected sum is…

Geometric Topology · Mathematics 2012-02-20 Zhiyun Cheng

Vassiliev invariants can be studied by studying the spaces of chord diagrams associated with singular knots. To these chord diagrams are associated the intersection graphs of the chords. We extend results of Chmutov, Duzhin and Lando to…

Geometric Topology · Mathematics 2009-09-25 Blake Mellor

It is known that the Kauffman-Murasugi-Thislethwaite type inequality becomes an equality for any (possibly virtual) adequate link diagram. We refine this condition. As an application we obtain a criterion for virtual link diagram with…

Geometric Topology · Mathematics 2021-03-29 Minori Okamura , Keiichi Sakai

We establish a Kauffman-Murasugi-Thistlethwaite-type theorem for alternating knots in a solid torus. Specifically, we show that any dotted-reduced alternating diagram of a knot in a handlebody realizes the minimal crossing number, and that…

Geometric Topology · Mathematics 2026-01-30 Lizzie Buchanan , Tanushree Shah

We construct graph-valued analogues of the Kuperberg sl(3) and G2 invariants for virtual knots. The restriction of the sl(3) or G2 invariants for classical knots coincides with the usual Homflypt sl(3) invariant and G2 invariants. For…

Geometric Topology · Mathematics 2014-07-11 Louis Hirsch Kauffman , Vassily Olegovich Manturov

A graph $G$ with vertex set $\{v_1,v_2,\ldots,v_n\}$ is an intersection graph of segments if there are segments $s_1,\ldots,s_n$ in the plane such that $s_i$ and $s_j$ have a common point if and only if $\{v_i,v_j\}$ is an edge of~$G$. In…

Computational Geometry · Computer Science 2014-06-11 Jiri Matousek

We extend the notion of intersection graphs for knots in the theory of finite type invariants to string links. We use our definition to develop weight systems for string links via the adjacency matrix of the intersection graph, and show…

Geometric Topology · Mathematics 2007-05-23 Blake Mellor

We prove that two horizontal-strip LLT polynomials are equal if the associated weighted graphs defined by the author in a previous paper are isomorphic. This provides a sufficient condition for equality of horizontal-strip LLT polynomials…

Combinatorics · Mathematics 2021-10-18 Foster Tom

We investigate an application of crossing parity for the bracket expansion of the Jones polynomial for virtual knots. In addition we consider an application of parity for the arrow polynomial as well as for the categorifications of both…

Geometric Topology · Mathematics 2011-10-25 Aaron Kaestner , Louis H. Kauffman

We formulate the notion of an isomorphism of GKM graphs. We then show that two GKM graphs have isomorphic graph equivariant cohomology algebras if and only if the graphs are isomorphic.

Algebraic Topology · Mathematics 2019-12-30 Matthias Franz , Hitoshi Yamanaka

We prove that if a finite order knot invariant does not distinguish mutant knots, then the corresponding weight system depends on the intersection graph of a chord diagram rather than on the diagram itself. The converse statement is easy…

Geometric Topology · Mathematics 2016-01-20 S. V. Chmutov , S. K. Lando

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

In this paper we introduce a new invariant of virtual knots and links that is non-trivial for infinitely many virtuals, but is trivial on classical knots and links. The invariant is initially be expressed in terms of a relative of the…

Geometric Topology · Mathematics 2007-05-23 Louis H. Kauffman

For smooth convex disks $A$, i.e., convex compact subsets of the plane with non-empty interior, we classify the classes $G^{\text{hom}}(A)$ and $G^{\text{sim}}(A)$ of intersection graphs that can be obtained from homothets and similarities…

Computational Geometry · Computer Science 2021-08-11 Mikkel Abrahamsen , Bartosz Walczak