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Related papers: Crosscap numbers of 2-bridge knots

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We consider systems of simple closed curves on surfaces and their total number of intersection points, their so-called crossing number. For a fixed number of curves, we aim to minimise the crossing number. We determine the minimal crossing…

Geometric Topology · Mathematics 2024-03-11 Jasmin Jörg

We investigate the bi-orderability of two-bridge knot groups and the groups of knots with 12 or fewer crossings by applying recent theorems of Chiswell, Glass and Wilson. Amongst all knots with 12 or fewer crossings (of which there are…

Algebraic Topology · Mathematics 2019-08-15 Adam Clay , Colin Desmarais , Patrick Naylor

Experimental data from Dunfield et al using random grid diagrams suggests that the genus of a knot grows linearly with respect to the crossing number. Using billiard table diagrams of Chebyshev knots developed by Koseleff and Pecker and a…

Geometric Topology · Mathematics 2021-08-03 Moshe Cohen

This paper employs various computational techniques to determine the bridge numbers of both classical and virtual knots. For classical knots, there is no ambiguity of what the bridge number means. For virtual knots, there are multiple…

Geometric Topology · Mathematics 2024-05-10 Hanh Vo , Puttipong Pongtanapaisan , Thieu Nguyen

For a torus knot K, we bound the crosscap number c(K) in terms of the genus g(K) and crossing number n(K): c(K) \leq [(g(K)+9)/6] and c(K) \leq [(n(K) + 16)/12]. The (6n-2,3) torus knots show that these bounds are sharp.

Geometric Topology · Mathematics 2007-05-23 Thomas W. Mattman , Owen Sizemore

We consider the relationship between the crosscap number $\gamma$ of knots and a partial order on the set of all prime knots, which is defined as follows. For two knots $K$ and $J$, we say $K \geq J$ if there exists an epimorphism…

Geometric Topology · Mathematics 2021-03-12 Jim Hoste , Patrick D. Shanahan , Cornelia A. Van Cott

We specify the computational complexity of crosscap numbers of alternating knots by introducing an automatic computation. For an alternating knot $K$, let $\cal{E}$ be the number of edges of its diagram. Then there exists a code such that…

Geometric Topology · Mathematics 2023-03-20 Kaito Yamada , Noboru Ito

We study the degree of polynomial representations of knots. We give the lexicographic degree of all two-bridge knots with 11 or fewer crossings. First, we estimate the total degree of a lexicographic parametrisation of such a knot. This…

Geometric Topology · Mathematics 2018-09-14 Erwan Brugallé , Pierre-Vincent Koseleff , Daniel Pecker

We give a list of minimal grid diagrams of the 13 crossing prime nonalternating knots which have arc index 13. There are 9,988 prime knots with crossing number 13. Among them 4,878 are alternating and have arc index 15. Among the other…

Geometric Topology · Mathematics 2024-02-06 Hwa Jeong Lee , Yoonsang Lee , Chanmin Lee , Yeseo Park , Hun Kim , Gyo Taek Jin

We define the concordance crosscap number of a knot as the minimum crosscap number among all the knots concordant to the knot. The four-dimensional crosscap number is the minimum first Betti number of non-orientable surfaces smoothly…

Geometric Topology · Mathematics 2007-05-23 Gengyu Zhang

This paper concerns the H(2)-unknotting numbers of links related to 2-bridge links. It consists of three parts. In the first part, we consider a necessary and sufficient condition for a 2-bridge link to have H(2)-unknotting number one. The…

Geometric Topology · Mathematics 2011-04-25 Yuanyuan Bao

The crosscap number of a knot in the 3-sphere is defined as the minimal first Betti number of non-orientable subsurfaces bounded by the knot. In this paper, we determine the crosscap numbers of pretzel knots. The key ingredient to obtain…

Geometric Topology · Mathematics 2007-05-23 Kazuhiro Ichihara , Shigeru Mizushima

In this paper, we characterize closed incompressible surfaces of genus two in the complements of 3-bridge knots and links. This characterization includes that of essential 2-string tangle decompositions for 3-bridge knots and links.

Geometric Topology · Mathematics 2007-05-23 Makoto Ozawa

Using exhaustive techniques and results from Lackenby and many others, we compute the tunnel number of all 1655 alternating 11 and 12 crossing knots and of 881 non-alternating 11 and 12 crossing knots. We also find all 5525 Montesinos knots…

Geometric Topology · Mathematics 2022-03-23 Felipe Castellano-Macías , Nicholas Owad

In this paper, we discuss the region unknotting number of different classes of 2-bridge knots. In particular, we provide region unknotting number for the classes of $2$-bridge knots whose Conway notation is $C(m,\ n), C(m,\ 2,\ m),$ $ C(m,\…

Geometric Topology · Mathematics 2014-07-11 Vikash Siwach , Prabhakar Madeti

In a previous work, the first and third authors studied a random knot model for all two-bridge knots using billiard table diagrams. Here we present a closed formula for the distribution of the crossing numbers of such random knots. We also…

Geometric Topology · Mathematics 2018-08-13 Moshe Cohen , Chaim Even-Zohar , Sunder Ram Krishnan

We describe the genus two knots which admit a genus one, one bridge position. These are divided into several families, one consists of vertical bandings of two genus one $(1,1)$-knots, other consists of vertical bandings of two cross cap…

Geometric Topology · Mathematics 2016-03-29 Mario Eudave-Muñoz , Fabiola Manjarrez-Gutierrez , Enrique Ramirez-Losada

Frequently, knots are enumerated by their crossing number. However, the number of knots with crossing number $c$ grows exponentially with $c$, and to date computer-assisted proofs can only classify diagrams up to around twenty crossings.…

Geometric Topology · Mathematics 2018-12-03 Yoav Moriah , Jessica S. Purcell

Negami found an upper bound on the stick number $s(K)$ of a nontrivial knot $K$ in terms of the minimal crossing number $c(K)$ of the knot which is $s(K) \leq 2 c(K)$. Furthermore McCabe proved $s(K) \leq c(K) + 3$ for a $2$-bridge knot or…

Geometric Topology · Mathematics 2014-11-10 Youngsik Huh , Sungjong No , Seungsang Oh

We give the bridge indices for 11-crossing prime knots and give a minimal bridge projection for each of these knots. The results on the indices may be easily summarized: all of these knots that are not rational knots or Montesinos knots…

Geometric Topology · Mathematics 2012-09-18 Chad Musick