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Related papers: Augmentations and Rulings of Legendrian Knots

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We show that there exists a Legendrian knot with maximal Thurston-Bennequin invariant whose contact homology is trivial. We also provide another Legendrian knot which has the same knot type and classical invariants but nonvanishing contact…

Symplectic Geometry · Mathematics 2017-08-03 Steven Sivek

This is an introduction to Legendrian contact homology and the Chekanov-Eliashberg differential graded algebra, with a focus on the setting of Legendrian knots in $\mathbb{R}^3$. This is the published version of the paper, but with a…

Symplectic Geometry · Mathematics 2023-04-21 John B. Etnyre , Lenhard L. Ng

For a Legendrian link $\Lambda \subset J^1M$ with $M = \mathbb{R}$ or $S^1$, immersed exact Lagrangian fillings $L \subset \mbox{Symp}(J^1M) \cong T^*(\mathbb{R}_{>0} \times M)$ of $\Lambda$ can be lifted to conical Legendrian fillings…

Symplectic Geometry · Mathematics 2023-01-23 Yu Pan , Dan Rutherford

The braid variety of a positive braid and the augmentation variety of a Legendrian link both admit decompositions coming from weaves and rulings, respectively. We prove that these decompositions agree under an isomorphism between the braid…

Symplectic Geometry · Mathematics 2025-08-29 Johan Asplund , Orsola Capovilla-Searle , James Hughes , Caitlin Leverson , Wenyuan Li , Angela Wu

Theory is developed for linear-quadratic at infinity generating families for Legendrian knots in R^3. It is shown that the unknot with maximal Thurston--Bennequin invariant of -1 has a unique linear-quadratic at infinity generating family,…

Geometric Topology · Mathematics 2009-04-20 Jill Jordan , Lisa Traynor

We define ruling invariants for even-valence Legendrian graphs in standard contact three-space. We prove that rulings exist if and only if the DGA of the graph, introduced by the first two authors, has an augmentation. We set up the usual…

Symplectic Geometry · Mathematics 2019-11-21 Byung Hee An , Youngjin Bae , Tamás Kálmán

This work applies the ideas of persistent homology to the problem of distinguishing Legendrian knots. We develop a persistent version of Legendrian contact homology by filtering the Chekanov-Eliashberg DGA using the action (height)…

Symplectic Geometry · Mathematics 2023-12-15 Maya Basu , Austin Christian , Ethan Clayton , Daniel Irvine , Fredrick Mooers , Weizhe Shen

In this paper we construct an $\mathcal{A}_\infty$-category associated to a Legendrian submanifold of jet spaces. Objects of the category are augmentations of the Chekanov algebra $\mathcal{A}(\Lambda)$ and the homology of the morphism…

Symplectic Geometry · Mathematics 2013-05-14 Frédéric Bourgeois , Baptiste Chantraine

We prove that every Legendrian knot in the tight contact structure of the 3-sphere is determined by the contactomorphism type of its exterior. Moreover, by giving counterexamples we show this to be not true for Legendrian links in the tight…

Geometric Topology · Mathematics 2026-02-10 Marc Kegel

In this article, associated to a (bordered) Legendrian graph, we study and show the equivalence between two categorical Legendrian isotopy invariants: the augmentation category, a unital $A_{\infty}$-category, which lifts the set of…

Symplectic Geometry · Mathematics 2025-09-29 Byung Hee An , Youngjin Bae , Tao Su

Legendrian contact homology (LCH) and its associated differential graded algebra are powerful non-classical invariants of Legendrian knots. Linearization makes the LCH computationally tractable at the expense of discarding nonlinear (and…

Symplectic Geometry · Mathematics 2009-01-06 Gokhan Civan , John B. Etnyre , Paul Koprowski , Joshua M. Sabloff , Alden Walker

We show that the set of augmentations of the Chekanov-Eliashberg algebra of a Legendrian link underlies the structure of a unital A-infinity category. This differs from the non-unital category constructed in [BC], but is related to it in…

Symplectic Geometry · Mathematics 2021-01-01 Lenhard Ng , Dan Rutherford , Vivek Shende , Steven Sivek , Eric Zaslow

If a Legendrian knot $\Lambda$ in the standard contact 3-sphere bounds an orientable exact Lagrangian surface $\Sigma$ in the standard symplectic 4-ball, then the genus of $\Sigma$ is equal to the slice genus of (the smooth knot underlying)…

Symplectic Geometry · Mathematics 2018-03-16 Tolga Etgü

Legendrian Contact Homology (LCH) and its augmentations are important invariants of Legendrian submanifolds, and for Legendrian knots in the standard contact 3-space in particular. We increase understanding of the algebraic structure of LCH…

Symplectic Geometry · Mathematics 2025-09-03 Jiajie Ma , Joshua M. Sabloff

In a recent work of I.\,Dynnikov and M.\,Prasolov a new method of comparing Legendrian knots is proposed. In general, to apply the method requires a lot of technical work. In particular, one needs to search all rectangular diagrams of…

Geometric Topology · Mathematics 2023-06-21 Ivan Dynnikov , Vladimir Shastin

The conormal lift of a link $K$ in $\R^3$ is a Legendrian submanifold $\Lambda_K$ in the unit cotangent bundle $U^* \R^3$ of $\R^3$ with contact structure equal to the kernel of the Liouville form. Knot contact homology, a topological link…

Symplectic Geometry · Mathematics 2014-11-11 Tobias Ekholm , John Etnyre , Lenhard Ng , Michael Sullivan

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

We use the contact invariant defined in [2] to construct a new invariant of Legendrian knots in Kronheimer and Mrowka's monopole knot homology theory (KHM), following a prescription of Stipsicz and V\'ertesi. Our Legendrian invariant…

Symplectic Geometry · Mathematics 2019-02-12 John A. Baldwin , Steven Sivek

We study some properties of decomposable exact Lagrangian cobordisms between Legendrian links in $\mathbb{R}^3$ with the standard contact structure. In particular, for any decomposable exact Lagrangian filling $L$ of a Legendrian link $K$,…

Geometric Topology · Mathematics 2015-12-29 Watchareepan Atiponrat

We consider S^1-families of Legendrian knots in the standard contact R^3. We define the monodromy of such a loop, which is an automorphism of the Chekanov-Eliashberg contact homology of the starting (and ending) point. We prove this…

Geometric Topology · Mathematics 2014-11-11 Tamas Kalman