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Introduced recently, an n-crossing is a singular point in a projection of a link at which n strands cross such that each strand travels straight through the crossing. We introduce the notion of an \"ubercrossing projection, a knot…

This paper, to be regularly updated, lists those prime knots with the fewest possible number of crossings for which values of basic knot invariants, such as the unknotting number or the smooth 4-genus, are unknown. This list is being…

Geometric Topology · Mathematics 2018-08-16 Jae Choon Cha , Charles Livingston

This paper is expository and is accessible to students. We define simple invariants of knots or links (linking number, Arf-Casson invariants and Alexander-Conway polynomials) motivated by interesting results whose statements are accessible…

Geometric Topology · Mathematics 2021-12-15 A. Skopenkov

Introducing a way to modify knots using $n$-trivial rational tangles, we show that knots with given values of Vassiliev invariants of bounded degree can have arbitrary unknotting number (extending a recent result of Ohyama, Taniyama and…

Geometric Topology · Mathematics 2007-05-23 A. Stoimenow

The aim of this paper is to realise the techniques of picture-valued invariants and invariants valued in free groups for long knots in the full torus. Such knots and links are of a particular interest because of their relation to Legendrian…

Algebraic Topology · Mathematics 2021-09-16 Sera Kim , Seongjeong Kim , Vassily Olegovich Manturov

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

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

Using the techniques on annulus twists, we observe that $6_3$ has infinitely many non-characterizing slopes, which affirmatively answers a question by Baker and Motegi. Furthermore, we prove that the knots $6_2$, $6_3$, $7_6$, $7_7$, $8_1$,…

Geometric Topology · Mathematics 2021-03-09 Tetsuya Abe , Keiji Tagami

Knot colorings are one of the simplest ways to distinguish knots, dating back to Reidemeister, and popularized by Fox. In this mostly expository article, we discuss knot invariants like colorability, knot determinant and number of…

Geometric Topology · Mathematics 2019-10-18 Sudipta Kolay

The lattice stick number of knots is defined to be the minimal number of straight sticks in the cubic lattice required to construct a lattice stick presentation of the knot. We similarly define the lattice stick number $s_{L}(G)$ of spatial…

Geometric Topology · Mathematics 2018-06-27 Hyungkee Yoo , Chaeryn Lee , Seungsang Oh

A rational knot or link can be put into a standard alternating format which has horizontal and vertical twist sites (double helices). The number and type of these twist sites are determined by terms of next-to-highest $z$-degree in…

Geometric Topology · Mathematics 2014-10-02 Mark E. Kidwell , Kerry M. Luse

Torus knots are an important family of knots about which much is understood; invariants of torus knots often exhibit nice formulas, making them convenient and fundamental building blocks for examples in knot theory. Spiral knots, defined…

Geometric Topology · Mathematics 2025-06-24 Sarah Blackwell , Ashish Das , Sydney Mayer , Luke Moyar , Faisal Quraishi , Ryan Stees

This manuscript introduces a new framework for the study of knots by exploring the neighborhood of knot embeddings in the space of simple open and closed curves in 3-space. The latter gives rise to a knotoid spectrum, which determines the…

Geometric Topology · Mathematics 2024-10-22 Eleni Panagiotou

In this paper we discuss the applications of knotoids to modelling knots in open curves and produce new knotoid invariants. We show how invariants of knotoids generally give rise to well-behaved measures of how much an open curve is…

Geometric Topology · Mathematics 2023-06-14 Wout Moltmaker , Roland van der Veen

In 2013, Adams introduced the $n$-crossing number of a knot $K$, denoted by $c_n(K)$. Inequalities between the $2$-, $3$-, $4$-, and $5$-crossing numbers have been previously established. We prove $c_9(K)\leq c_3(K)-2$ for all knots $K$…

Geometric Topology · Mathematics 2023-10-18 Nicholas Hagedorn

The slicing degree of a knot $K$ is defined as the smallest integer $k$ such that $K$ is $k$-slice in $\#^n \overline{\mathbb{CP}^2}$ for some $n$. In this paper, we establish bounds for the slicing degrees of knots using Rasmussen's…

Geometric Topology · Mathematics 2024-04-25 Qianhe Qin

The combinatorial approach to knot theory treats knots as diagrams modulo Reidemeister moves. Many constructions of knot invariants (e.g., index polynomials, quandle colorings, etc.) use elements of diagrams such as arcs and crossings by…

Geometric Topology · Mathematics 2025-04-29 Igor Nikonov

Given a band sum of a split two-component link along a nontrivial band, we obtain a family of knots indexed by the integers by adding any number of full twists to the band. We show that the knots in this family have the same Heegaard knot…

Geometric Topology · Mathematics 2023-02-01 Joshua Wang

Let \nu be any integer-valued additive knot invariant that bounds the smooth 4-genus of a knot K, |\nu(K)| <= g_4(K), and determines the 4-ball genus of positive torus knots, \nu(T_{p,q}) = (p-1)(q-1)/2. Either of the knot concordance…

Geometric Topology · Mathematics 2009-03-10 Charles Livingston , Swatee Naik

We consider knot theories possessing a {\em parity}: each crossing is decreed {\em odd} or {\em even} according to some universal rule. If this rule satisfies some simple axioms concerning the behaviour under Reidemeister moves, this leads…

Geometric Topology · Mathematics 2009-12-31 Vassily Olegovich Manturov