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Related papers: On Rack Invariants Of Legendrian Knots

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We define a new algebraic structure called Legendrian racks or racks with Legendrian structure, motivated by the front-projection Reidemeister moves for Legendrian knots. We provide examples of Legendrian racks and use these algebraic…

Geometric Topology · Mathematics 2021-01-26 Jose Ceniceros , Mohamed Elhamdadi , Sam Nelson

We present two different constructions of invariants for Legendrian knots in the standard contact space $\R^3$. These invariants are defined combinatorially, in terms of certain planar projections, and are useful in distinguishing…

Geometric Topology · Mathematics 2007-05-23 Yuri Chekanov

It is shown that Legendrian (resp. transverse) cable links in the 3-sphere with its standard tight contact structure, i.e. links consisting of an unknot and a cable of that unknot, are classified by their oriented link type and the…

Symplectic Geometry · Mathematics 2007-12-18 Fan Ding , Hansjörg Geiges

A generalised Legendrian rack is a rack equipped with a Legendrian structure, which is a pair of maps encoding the information of Legendrian Reidemeister moves together with up and down cusps in the front diagram of an oriented Legendrian…

Geometric Topology · Mathematics 2025-10-15 Biswadeep Karmakar , Deepanshi Saraf , Mahender Singh

We define relative versions of the classical invariants of Legendrian and transverse knots in contact 3-manifolds for knots that are homologous to a fixed reference knot. We show these invariants are well-defined and give some basic…

Symplectic Geometry · Mathematics 2009-09-25 Georgi D. Gospodinov

We show that for a big class of contact manifolds the groups of order $\leq n$ invariants (with values in an arbitrary Abelian group) of Legendrian, of transverse and of framed knots are canonically isomorphic. On the other hand for an…

Symplectic Geometry · Mathematics 2007-05-23 Vladimir Tchernov

The homology and cohomology of quandles and racks are used in knot theory: given a finite quandle and a cocycle, we can construct a knot invariant. This is a quick introductory survey to the invariants of knots derived from quandles and…

Geometric Topology · Mathematics 2007-05-23 Seiichi Kamada

Let E be a circle bundle over a Riemann surface that supports a contact structure transverse to the fibers. This paper presents a combinatorial definition of a differential graded algebra (DGA) that is an invariant of Legendrian knots in E.…

Symplectic Geometry · Mathematics 2007-05-23 Joshua M. Sabloff

We construct a combinatorial invariant of Legendrian knots in standard contact three-space. This invariant, which encodes rational relative Symplectic Field Theory and extends contact homology, counts holomorphic disks with an arbitrary…

Symplectic Geometry · Mathematics 2015-05-13 Lenhard Ng

The study of the Vassiliev invariants of Legendrian knots was started by D. Fuchs and S. Tabachnikov who showed that the groups of complex-valued Vassiliev invariants of Legendrian and of framed knots in the standard contact $R^3$ are…

Geometric Topology · Mathematics 2016-09-07 Vladimir Tchernov

We define ambient isotopy invariants of oriented knots and links using the counting invariants of framed links defined by finite racks. These invariants reduce to the usual quandle counting invariant when the rack in question is a quandle.…

Geometric Topology · Mathematics 2013-07-30 Sam Nelson

The aim of this paper is to define a homology theory for racks with finite rank N and use it to define invariants of knots generalizing the CJKLS 2-cocycle invariants related to the invariants defined in [15]. For this purpose, we prove…

Geometric Topology · Mathematics 2011-05-24 Mohamed Elhamdadi , Sam Nelson

The problem of classification of Legendrian knots (links) up to isotopy in the class of Legendrian embeddings (Legendrian isotopy) naturally leads to the following two subproblems. The first of them is: which combinations of the three…

Geometric Topology · Mathematics 2016-09-07 Yuri Chekanov

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

Associated to Legendrian links in the standard contact three-space, Ruling polynomials are Legendrian isotopy invariants, which also compute augmentation numbers, that is, the points-counting of augmentation varieties for Legendrian links…

Symplectic Geometry · Mathematics 2017-07-18 Tao Su

In this article, we explore a polynomial invariant for Legendrian knots which is a natural extension of Jones polynomial for (topological) knots. To this end, a new type of skein relation is introduced for the front projections of…

Geometric Topology · Mathematics 2025-10-07 Dheeraj Kulkarni , Monika Yadav

We present an atlas of Legendrian knots in standard contact three-space. This gives a conjectural Legendrian classification for all knots with arc index at most 9, including alternating knots through 7 crossings and nonalternating knots…

Symplectic Geometry · Mathematics 2013-05-08 Wutichai Chongchitmate , Lenhard Ng

The paper deals with topologically trivial Legendrian knots in tight and overtwisted contact 3-manifolds. The first part contains a thorough exposition of the proof of the classification of topologically trivial Legendrian knots (i.e.…

Geometric Topology · Mathematics 2008-11-16 Y. Eliashberg , M. Fraser

In this paper, we explore the algebraic structure of GL-racks, and demonstrate that finite GL-racks decompose canonically into permutation GL-racks and block GL-racks. As a corollary, we verify that two Legendrian knots with the same…

Geometric Topology · Mathematics 2026-05-19 Zhiyun Cheng , Zhiyi He

In this paper we define invariants for primitive Legendrian knots in lens spaces L(p,q) for q not equal to 1. The main invariant is a differential graded algebra which is computed from a labeled Lagrangian projection of the pair (L(p,q),…

General Topology · Mathematics 2009-01-28 Joan E. Licata
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