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Related papers: Legendrian Non-Simple Two-Bridge Knots

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We prove a simple necessary and sufficient condition for a two-bridge knot K(p,q) to be quasipositive, based on the continued fraction expansion of p/q. As an application, coupled with some classification results in contact and symplectic…

Geometric Topology · Mathematics 2025-05-09 Burak Ozbagci

We call a knot in the 3-sphere $SU(2)$-simple if all representations of the fundamental group of its complement which map a meridian to a trace-free element in $SU(2)$ are binary dihedral. This is a generalisation of being a 2-bridge knot.…

Geometric Topology · Mathematics 2017-02-15 Raphael Zentner

We give a purely combinatorial proof of a K\"{u}nneth formula for the minus version of knot Floer homology of connected sums by constructing a quasi-isomorphism of grid chain complexes. The quasi-isomorphism naturally deduces that the…

Geometric Topology · Mathematics 2024-04-23 Hajime Kubota

We introduce a simple combinatorial method for computing all versions of the knot Floer homology of the preimage of a two-bridge knot K(p,q) inside its double-branched cover, -L(p,q). The 4-pointed genus 1 Heegaard diagram we obtain looks…

Geometric Topology · Mathematics 2007-05-23 J. Elisenda Grigsby

We prove that each overtwisted contact structure has knot types that are represented by infinitely many distinct transverse knots all with the same self-linking number. In some cases, we can even classify all such knots. We also show…

Symplectic Geometry · Mathematics 2012-01-04 John B. Etnyre

Using contact-geometric techniques and sutured Floer homology, we present an alternate formulation of the minus and plus version of knot Floer homology. We further show how natural constructions in the realm of contact geometry give rise to…

Geometric Topology · Mathematics 2017-06-14 John B. Etnyre , David Shea Vela-Vick , Rumen Zarev

Given a connected cobordism between two knots in the 3-sphere, our main result is an inequality involving torsion orders of the knot Floer homology of the knots, and the number of local maxima and the genus of the cobordism. This has…

Geometric Topology · Mathematics 2020-11-04 András Juhász , Maggie Miller , Ian Zemke

In this note, we observe that the hat version of the Heegaard Floer invariant of Legendrian knots in contact three-manifolds defined by Lisca-Ozsvath-Stipsicz-Szabo can be combinatorially computed. We rely on Plamenevskaya's combinatorial…

Geometric Topology · Mathematics 2021-03-16 Dongtai He , Linh Truong

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

We define several equivariant concordance invariants using knot Floer homology. We show that our invariants provide a lower bound for the equivariant slice genus and use this to give a family of strongly invertible slice knots whose…

Geometric Topology · Mathematics 2023-08-08 Irving Dai , Abhishek Mallick , Matthew Stoffregen

In the note we study Legendrian and transverse knots in rationally null-homologous knot types. In particular we generalize the standard definitions of self-linking number, Thurston-Bennequin invariant and rotation number. We then prove a…

Symplectic Geometry · Mathematics 2014-04-07 Kenneth L. Baker , John B. Etnyre

We use the Ozsvath-Szabo theory of Floer homology to define an invariant of knot complements in three-manifolds. This invariant takes the form of a filtered chain complex, which we call CF_r. It carries information about the Floer homology…

Geometric Topology · Mathematics 2007-05-23 Jacob Rasmussen

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

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

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

Symmetries of knots have been studied extensively, and strongly invertible knots are one of them. Lamm defined the equivariant crossing number $c_t(K)$, the minimum crossing number among all symmetric diagrams for a strongly invertible knot…

Geometric Topology · Mathematics 2023-04-04 Jundai Nanasawa

We investigate the question of when distinct branched surfaces in the complement of a 2-bridge knot support essential surfaces with identical boundary slopes. We determine all instances in which this occurs and identify an infinite family…

Geometric Topology · Mathematics 2015-02-17 Cynthia L. Curtis , William Franczak , Randolph J. Leiser , Ryan J. Manheimer

For a word w in the braid group on n-strands, we denote by T_w the corresponding transverse braid in the rotational symmetric tight contact structure on S^3. We exhibit a map on link Floer homology which sends the transverse invariant…

Geometric Topology · Mathematics 2016-01-20 John A. Baldwin

We partially determine grid homology (combinatorial knot Floer homology) of diagonal knots, which are conjectured to be equivalent to positive braid knots, by exploiting nice grid diagrams. Its next-to-top term detects the number of prime…

Geometric Topology · Mathematics 2025-07-18 Hajime Kubota

We develop purely algebraic methods for proving that a knot is prime. Our approach uses the Heegaard Floer polynomial in conjunction with classical knot-theoretic methods: cyclic, dihedral, and metacyclic covering spaces. The theory of…

Geometric Topology · Mathematics 2025-08-12 Samantha Allen , Charles Livingston