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Related papers: Average four-genus of two-bridge knots

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Given a knot in the 3-sphere, the non-orientable 4-genus or 4-dimensional crosscap number of a knot is the minimal first Betti number of non-orientable surfaces, smoothly and properly embedded in the 4-ball, with boundary the knot. In this…

Geometric Topology · Mathematics 2020-11-20 Nakisa Ghanbarian

To a Seifert matrix of a knot K one can associate a matrix w(K) with entries in the rational function field, Q(t). The Murasugi, Milnor, and Levine-Tristram knot signatures, all of which provide bounds on the 4-genus of a knot, are…

Geometric Topology · Mathematics 2013-10-29 Charles Livingston

Let c(K;F) denote the surface crossing number of a knot K with respect to a closed connected surface F in S^3. We relate c(K;F) to the tunnel number t(K) and to the Heegaard deficiency delta(F)=g(M_1;F)+g(M_2;F)-g(F), where S^3=M_1 union_F…

Geometric Topology · Mathematics 2026-05-22 Makoto Ozawa

For some families of two-bridge knots, including double-twist knots with genus at least four, we determine precisely the set of integers $n>1$ such that the fundamental group of the $n$-fold cyclic branched cover of the 3-sphere along these…

Geometric Topology · Mathematics 2020-02-26 Hannah Turner

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

In formulating a non-orientable analogue of the Milnor Conjecture on the $4$-genus of torus knots, Batson developed an elegant construction that produces a smooth non-orientable spanning surface in $B^4$ for a given torus knot in $S^3$.…

Geometric Topology · Mathematics 2023-03-16 Joshua M. Sabloff

We give an obstruction for genus one knots $K$, $K'$ to have the Gordian distance one by using the $0$th coefficient of the HOMFLT polynomials. As an application, we give a new constraint for genus one knot to admit a (generalized) cosmetic…

Geometric Topology · Mathematics 2022-10-21 Tetsuya Ito

We extend the equality-type results of Ito--Takimura and Kindred for the non-orientable genera of alternating knots to the setting of two-component alternating links. We show that, for such links, a unified quantity capturing both…

Geometric Topology · Mathematics 2026-02-06 Noboru Ito , Nodoka Kawajiri

The Turaev genus defines a natural filtration on knots where Turaev genus zero knots are precisely the alternating knots. We show that the signature of a Turaev genus one knot is determined by the number of components in its all-A Kauffman…

Geometric Topology · Mathematics 2025-08-19 Oliver T. Dasbach , Adam M. Lowrance

A knot K is called n-adjacent to the unknot, if K admits a projection containing n generalized crossings such that changing any m (no larger than n) of them yields a projection of the unknot. We show that a non-trivial satellite knot K is…

Geometric Topology · Mathematics 2007-05-23 Efstratia Kalfagianni , Xiao-Song Lin

We show that the torus knots $T(2,5)$ and $T(2,9)$ bound smooth M\"{o}bius bands in the 4-ball whose double branched covers are negative definite, giving counterexamples to Conjectures 1.6 and 1.8 of Allen in [New York J. Math. 29 (2023)…

Geometric Topology · Mathematics 2024-07-18 Kouki Sato

We study the double slice genus of a knot, a natural generalization of slice genus. We define a notion called band number, a natural generalization of band unknotting number, and prove it is an upper bound on double slice genus. Our bound…

Geometric Topology · Mathematics 2019-01-24 Clayton McDonald

We obtain new lower bounds of the minimal genus of a locally flat surface representing a 2-dimensional homology class in a topological 4-manifold with boundary, using the von Neumann-Cheeger-Gromov $\rho$-invariant. As an application our…

Geometric Topology · Mathematics 2007-05-23 Jae Choon Cha

In a 3-manifold M, let K be a knot and R be an annulus which meets K transversely. We define the notion of the pair (R,K) being caught by a surface Q in the exterior of the link given by K and the boundary curves of R. For a caught pair…

Geometric Topology · Mathematics 2016-03-09 Ken Baker , Cameron Gordon , John Luecke

We prove that any link admitting a diagram with a single negative crossing is strongly quasipositive. This answers a question of Stoimenow's in the (strong) positive. As a second main result, we give simple and complete characterizations of…

Geometric Topology · Mathematics 2022-09-05 Peter Feller , Lukas Lewark , Andrew Lobb

A knot K is called a 1-genus 1-bridge knot in a 3-manifold M if (M,K) has a Heegaard splitting (V_1,t_1)\cup (V_2,t_2) where V_i is a solid torus and t_i is a boundary parallel arc properly embedded in V_i. If the exterior of a knot has a…

Geometric Topology · Mathematics 2010-09-14 Hiroshi Goda , Chuichiro Hayashi

We give a complete classification of toroidal Seifert fibered surgeries on alternating knots. Precisely, we show that if an alternating knot admits a toroidal Seifert fibered surgery, then the knot is either the trefoil knot and the surgery…

Geometric Topology · Mathematics 2014-03-12 Kazuhiro Ichihara , In Dae Jong

In this paper, we study the Riley polynomial of double twist knots with higher genus. Using the root of the Riley polynomial, we compute the range of rational slope $r$ such that $r$-filling of the knot complement has left-orderable…

Geometric Topology · Mathematics 2022-05-16 Xinghua Gao

We model the typical behavior of knots and links using grid diagrams. Links are ubiquitous in the sciences, and their "normal" or "typical" behavior is of significant importance in understanding situations such as the topological state of…

Geometric Topology · Mathematics 2021-03-03 Margaret I. Doig

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