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The simultaneous crossing number is a new knot invariant which is defined for strongly invertible knots having diagrams with two orthogonal transvergent axes of strong inversions. Because the composition of the two inversions gives a cyclic…

Geometric Topology · Mathematics 2025-04-16 Christoph Lamm , Michael Eisermann

Traditionally, knot theorists have considered projections of knots where there are two strands meeting at every crossing. A triple crossing is a crossing where three strands meet at a single point, such that each strand bisects the…

Geometric Topology · Mathematics 2018-05-14 Daishiro Nishida

There are 46,972 prime knots with crossing number 14. Among them 19,536 are alternating and have arc index 16. Among the non-alternating knots, 17, 477, and 3,180 have arc index 10, 11, and 12, respectively. The remaining 23,762 have arc…

Generalizing unknotting number, $n$-adjacent knots have $n$ crossings such that changing any non-empty subset of them results in the unknot. In this paper, we determine the 2-adjacent knots through 12 crossings. Using Heegaard Floer…

Geometric Topology · Mathematics 2025-10-02 John Carney , Everett Meike

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

Binary representations of the trefoil and other knots of up to ten crossings in the simple cubic lattice were created. The BiEntropy of each knot was computed using a variety of binary encodings and compared against controls. This showed…

General Mathematics · Mathematics 2018-02-13 Grenville J. Croll

We prove that if an alternating 3-braid knot has unknotting number one, then there must exist an unknotting crossing in any alternating diagram of it, and we enumerate such knots. The argument combines the obstruction to unknotting number…

Geometric Topology · Mathematics 2009-02-11 Joshua Greene

Positive permutation braids on n strings, which are defined to be positive n-braids where each pair of strings crosses at most once, form the elementary but non-trivial building blocks in many studies of conjugacy in the braid groups. We…

Geometric Topology · Mathematics 2007-05-23 Hugh R. Morton , Richard J. Hadji

We show that a finite numerical boundary slope of an essential surface in the exterior of a Montesinos knot is bounded above and below in terms of the numbers of positive/negative crossings of a specific minimal diagram of the knot.

Geometric Topology · Mathematics 2008-09-26 Kazuhiro Ichihara , Shigeru Mizushima

Given a knot K we introduce a new invariant coming from the Blanchfield pairing and we show that it gives a lower bound on the unknotting number of K. This lower bound subsumes the lower bounds given by the Levine-Tristram signatures, by…

Geometric Topology · Mathematics 2015-05-27 Maciej Borodzik , Stefan Friedl

For a knot K, let b_n(K) be the minimum length of an n-stranded braid representative of K. Examples of knots exist for which b_n(K) is a non-increasing function. We investigate the behavior of b_n(K). We develop bounds on the function in…

Geometric Topology · Mathematics 2014-10-01 Cornelia A. Van Cott

We introduce an unknotting-type number of knot projections that gives an upper bound of the crosscap number of knots. We determine the set of knot projections with the unknotting-type number at most two, and this result implies classical…

Geometric Topology · Mathematics 2020-08-26 Noboru Ito , Yusuke Takimura

Previous work used polygonal realizations of knots to reduce the problem of computing the superbridge number of a realization to a linear programming problem, leading to new sharp upper bounds on the superbridge index of a number of knots.…

Geometric Topology · Mathematics 2022-11-14 Clayton Shonkwiler

We provide linear lower bounds for the signature of positive braids in terms of the three genus of their braid closure. This yields linear bounds for the topological slice genus of knots that arise as closures of positive braids.

Geometric Topology · Mathematics 2015-10-15 Peter Feller

A knot is an an embedding of a circle into three-dimensional space. We say that a knot is unknotted if there is an ambient isotopy of the embedding to a standard circle. By representing knots via planar diagrams, we discuss the problem of…

Geometric Topology · Mathematics 2011-11-08 Allison Henrich , Louis H. Kauffman

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

Unknotting numbers for torus knots and links are well known. In this paper, we present a method for determining the position of unknotting number crossing changes in a toric braid B(p, q) such that the closure of the resultant braid is…

Geometric Topology · Mathematics 2012-07-23 Vikash Siwach , Madeti Prabhakar

We define and compare several natural ways to compute the bridge number of a knot diagram. We study bridge numbers of crossing number minimizing diagrams, as well as the behavior of diagrammatic bridge numbers under the connected sum…

Geometric Topology · Mathematics 2021-07-09 Ryan Blair , Alexandra A. Kjuchukova , Makoto Ozawa

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

For any given number of crossings $c$, there exists a formula to determine the number of 2-bridge knots of $c$ crossings, and indeed it is a simple matter to actually construct presentations of these knots. However, the determination of…

Geometric Topology · Mathematics 2007-05-23 David De Wit