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Related papers: Equivariant crossing numbers for two-bridge knots

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Cohen, Lowrance, Madras, and Raanes computed the average (absolute value of) signature over all 2-bridge knots with crossing number $c$ by introducing the number $s(c,\sigma)$ of 2-bridge knots of crossing number $c$ and signature $\sigma$.…

Geometric Topology · Mathematics 2026-04-24 Cody Baker , Moshe Cohen , Henry Dam , Rebecca Felber , Neal Madras , Ritvik Saha , Daisy Thackrah

By examining knot Floer homology, we extend a result of Ozsv\'ath and Stipsicz and show further infinitely many Legendrian and transversely non-simple knot types among two-bridge knots. We give sufficient conditions of Legendrian and…

Symplectic Geometry · Mathematics 2020-04-03 Viktória Földvári

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

Using unknotting number, we introduce a link diagram invariant of Hass and Nowik type, which changes at most by 2 under a Reidemeister move. As an application, we show that a certain infinite sequence of diagrams of the trivial…

Geometric Topology · Mathematics 2010-12-27 Chuichiro Hayashi , Miwa Hayashi

We use the degree of the colored Jones knot polynomials to show that the crossing number of a $(p,q)$-cable of an adequate knot with crossing number $c$ is larger than $q^2\, c$. As an application we determine the crossing number of…

Geometric Topology · Mathematics 2025-05-05 Efstratia Kalfagianni , Rob Mcconkey

The connected sum of two flat virtual knots depends on the choice of diagrams and basepoints. We show that any minimal crossing diagram of a composite flat virtual knot is a connected sum diagram. We also show the crossing number of flat…

Geometric Topology · Mathematics 2024-07-26 Jie Chen

The braid indices of most links remain unknown as there is no known universal method that can be used to determine the braid index of an arbitrary knot. This is also the case for alternating knots. In this paper, we show that if $K$ is an…

Geometric Topology · Mathematics 2024-08-28 Yuanan Diao , Hugh Morton

The crossing number of a graph $G$ is the minimum number of edge crossings over all drawings of $G$ in the plane. A graph $G$ is $k$-crossing-critical if its crossing number is at least $k$, but if we remove any edge of $G$, its crossing…

Combinatorics · Mathematics 2020-09-22 János Barát , Géza Tóth

Algorithm of construction of all knots, links with given number of crosses on diagram of knot, link is offered. This algorithm is based on simple proposition, that there is a representation of knot (link) as closure of braid with n threads…

Geometric Topology · Mathematics 2007-05-23 S. S. Serova , S. A. Serov

Given a knot K in S^3, let u^-(K) (respectively, u^+(K)) denote the minimum number of negative (respectively, positive) crossing changes among all unknotting sequences for K. We use knot Floer homology to construct the invariants l^-(K),…

Geometric Topology · Mathematics 2021-01-06 Akram Alishahi , Eaman Eftekhary

We show that the average or expected absolute value of the signatures of all 2-bridge knots with crossing number $c$ approaches $\sqrt{{2c}/{\pi}}$. Baader, Kjuchukova, Lewark, Misev, and Ray consider a model for 2-bridge knot diagrams…

Geometric Topology · Mathematics 2024-06-26 Moshe Cohen , Adam M. Lowrance , Neal Madras , Steven Raanes

We present the complete classification of the subgroup of the classical knot concordance group generated by knots with eight or fewer crossings. Proofs are presented in summary. We also describe extensions of this work to the case of nine…

Geometric Topology · Mathematics 2020-09-01 Julia Collins , Paul Kirk , Charles Livingston

In 2000, Habiro introduced the notion of $C_k$-equivalence of knots and links. This geometric filtration is closely connected to finite type invariants, a class of invariants including Milnor's invariants. Shortly thereafter, Ohyama,…

Geometric Topology · Mathematics 2026-05-06 Anthony Bosman , Christopher W. Davis , Taylor Martin , Katherine Vance

A knot is called minimal if its knot group admits epimorphisms onto the knot groups of only the trivial knot and itself. In this paper, we determine which two-bridge knot $\mathfrak{b}(p,q)$ is minimal where $q \leq 6$ or $p \leq 100$.

Geometric Topology · Mathematics 2016-09-09 Fumikazu Nagasato , Masaaki Suzuki , Anh T. Tran

We define the symmetric braid index $b_s(K)$ of a ribbon knot $K$ to be the smallest index of a braid whose closure yields a symmetric union diagram of $K$, and derive a Khovanov-homological characterisation of knots with $b_s(K)$ at most…

Geometric Topology · Mathematics 2025-10-08 Vitalijs Brejevs , Feride Ceren Kose

The average genus of a 2-bridge knot with crossing number $c$ approaches $\frac{c}{4} + \frac{1}{12}$ as $c$ approaches infinity, as proven by Suzuki and Tran and independently Cohen and Lowrance. In this paper, for the genera of $2$-bridge…

In [14], the second named author constructed the bracket invariant [.] of virtual knots valued in pictures (linear combinations of virtual knot diagrams with some crossing information omitted), such that for many diagrams K, the following…

Geometric Topology · Mathematics 2017-01-24 Denis P. Ilyutko , Vassily O. Manturov

We prove that fibred knots cannot be untied with $\bar{t}_{2k}$-moves, for all $k \geq 2$. More generally, we give an upper bound on the number of two strand twist operations that allow to untie a knot with non-trivial HOMFLY polynomial, in…

Geometric Topology · Mathematics 2022-09-15 Lambert A'Campo , Sebastian Baader , Livio Ferretti , Levi Ryffel

We explore a knot invariant derived from colorings of corresponding $1$-tangles with arbitrary connected quandles. When the quandle is an abelian extension of a certain type the invariant is equivalent to the quandle $2$-cocycle invariant.…

Geometric Topology · Mathematics 2016-08-09 W. Edwin Clark , Larry A. Dunning , Masahico Saito

An upper bound of the superbridge index of the connected sum of two knots is given in terms of the braid index of the summands. Using this upper bound and minimal polygonal presentations, we give an upper bound in terms of the superbridge…

Geometric Topology · Mathematics 2007-05-23 Gyo Taek Jin