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Related papers: A new algorithm for recognizing the unknot

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In this article, we propose the approach to procedural optimization of a neural network, based on the combination of information theory and braid theory. The network studied in the article implemented with the intersections between the…

Neural and Evolutionary Computing · Computer Science 2021-04-21 Olga Lukyanova , Oleg Nikitin , Alex Kunin

We consider countable linear orders and study the quasi-order of convex embeddability and its induced equivalence relation. We obtain both combinatorial and descriptive set-theoretic results, and further extend our research to the case of…

Logic · Mathematics 2025-05-06 Martina Iannella , Alberto Marcone , Luca Motto Ros , Vadim Weinstein

Many natural counting problems arise in connection with the normal form of braids--and seem to have never been considered so far. Here we solve some of them by analysing the normality condition in terms of the associated permutations, their…

Combinatorics · Mathematics 2007-05-23 Patrick Dehornoy

An implementation of BFACF-style algorithms on knotted polygons in the simple cubic, face centered cubic and body centered cubic lattice is used to estimate the statistics and writhe of minimal length knotted polygons in each of the…

Statistical Mechanics · Physics 2015-05-28 E. J. Janse van Rensburg , A. Rechnitzer

A {\it stuck knot} is a knot diagram containing designated crossings, called {\it stuck crossings}, whose incident strands are required to remain locally non-separable. These rigidity constraints restrict the allowable ambient isotopies and…

Geometric Topology · Mathematics 2026-02-23 Ioannis Diamantis

We take a close look at a classical magic trick performed with a string, where a trivial knot is seemingly isotoped into a trefoil, and generalize it to a family of magic tricks for transforming the unknot into other knots. We encode such a…

Geometric Topology · Mathematics 2026-04-16 Raphael Appenzeller , José Pedro Quintanilha

We partially determine grid homology (combinatorial knot Floer homology) of diagonal knots, which are conjectured to be equivalent to positive braid knots, by exploiting nice grid diagrams. Its next-to-top term detects the number of prime…

Geometric Topology · Mathematics 2025-07-18 Hajime Kubota

An $n$-plat 1-knot is one isotopic to the plat closure of some $2n$-braid, which is also called an $n$-bridge 1-knot. Schubert classified 2-bridge 1-knots by considering their double branched covers which are homeomorphic to lens spaces. A…

Geometric Topology · Mathematics 2026-05-05 Jumpei Yasuda

A knot is a circle piecewise-linearly embedded into the 3-sphere. The topology of a knot is intimately related to that of its exterior, which is the complement of an open regular neighborhood of the knot. Knots are typically encoded by…

Geometric Topology · Mathematics 2023-03-20 Nathan M. Dunfield , Malik Obeidin , Cameron Gates Rudd

The first algorithm for sampling the space of thick equilateral knots, as a function of thickness, will be described. This algorithm is based on previous algorithms of applying random reflections. To prove the existence of the algorithm, we…

Geometric Topology · Mathematics 2017-05-09 Kyle Chapman

We define a knot to be $\gamma_0$-sharp if its Seifert genus is detected by the concordance invariant $\gamma_0$, which arises from the immersed curve formalism in bordered Heegaard Floer homology. We show that a connected sum of…

Geometric Topology · Mathematics 2025-07-29 Jennifer Hom , JungHwan Park

A matching cut is a partition of the vertex set of a graph into two sets $A$ and $B$ such that each vertex has at most one neighbor in the other side of the cut. The MATCHING CUT problem asks whether a graph has a matching cut, and has been…

Data Structures and Algorithms · Computer Science 2019-05-09 Guilherme C. M. Gomes , Ignasi Sau

The Wang tiling is a classical problem in combinatorics. A major theoretical question is to find a (small) set of tiles which tiles the plane only aperiodically. In this case, resulting tilings are rather restrictive. On the other hand,…

Discrete Mathematics · Computer Science 2017-05-09 Alexandre Derouet-Jourdan , Shizuo Kaji , Yoshihiro Mizoguchi

The braid group has recently attracted much attention. This is primarily based upon the discovery of its usage in various cryptosystems [AAG],[KLCHKP]. One major focus of current research has been in solving decision problems in braid…

Group Theory · Mathematics 2007-05-23 Elie Feder

We prove that any arc-presentation of the unknot admits a monotonic simplification by elementary moves; this yields a simple algorithm for recognizing the unknot. We obtain similar results for split links and composite links.

Geometric Topology · Mathematics 2013-10-22 Ivan Dynnikov

This work is concerned with an inverse elastic scattering problem of identifying the unknown rigid obstacle embedded in an open space filled with a homogeneous and isotropic elastic medium. A Newton-type iteration method relying on the…

Numerical Analysis · Mathematics 2023-10-13 Yan Chang , Yukun Guo , Hongyu Liu , Deyue Zhang

We give an algorithm to decide whether a given braid with four strings is a product of three factors which are conjugates of standard generators of the braid group. The algorithm is of polynomial time. It is based on the Garside theory. We…

Group Theory · Mathematics 2024-12-04 Stepan Yu. Orevkov

Ozsv\'ath and Szab\'o conjectured that knot Floer homology detects fibred knots in $S^3$. We will prove this conjecture for null-homologous knots in arbitrary closed 3--manifolds. Namely, if $K$ is a knot in a closed 3--manifold $Y$, $Y-K$…

Geometric Topology · Mathematics 2009-11-11 Yi Ni

We continue the study of the genus of knot diagrams, deriving a new description of generators using Hirasawa's algorithm. This description leads to good estimates on the maximal number of crossings of generators and allows us to complete…

Geometric Topology · Mathematics 2015-03-17 A. Stoimenow

We introduce the Alexander-Beck module of a knot as a canonical refinement of the classical Alexander module, and we prove that this new invariant is an unknot-detector.

Geometric Topology · Mathematics 2019-04-12 Markus Szymik