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Related papers: On Legendrian curves in $\mathbb P^3$

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We show that all positive contact surgeries on every Legendrian figure-eight knot in $(S^3, \xi_{\rm{std}})$ result in an overtwisted contact structure. The proof uses convex surface theory and invariants from Heegaard Floer homology.

Geometric Topology · Mathematics 2016-10-14 James Conway

This note (which makes no claim to novelty) presents a proof of the separable rational connectedness of smooth cubic hypersurfaces, in any characteristic, by showing how to explicitly construct very free curves (of degree 3) on them. -----…

Algebraic Geometry · Mathematics 2007-05-23 David A. Madore

Let $S$ be a projective plane with $3$ holes. We prove that there is an exhaustion of the curve complex $\mathcal{C}(S)$ by a sequence of finite rigid sets. As a corollary, we obtain that the group of simplicial automorphisms of…

Geometric Topology · Mathematics 2019-07-23 Błażej Szepietowski

Let C be a non-hyperelliptic algebraic curve of genus at least 3. Enriques and Babbage proved that its canonical image is the intersection of the quadrics that contain it, except when C is trigonal (that is, it has a linear system of degree…

Algebraic Geometry · Mathematics 2011-03-25 Josef Schicho , David Sevilla

We study linear systems cut out by cones of fixed degree on a smooth complex curve $C\subset\mathbb{P}^{3}$. We develop a systematic study of the families of such systems, considering their limits, their infinitesimal behaviour and some…

Algebraic Geometry · Mathematics 2025-11-14 Riccardo Moschetti , Gian Pietro Pirola , Lidia Stoppino

Using an explicit family of plane quartic curves, we prove the existence of a genus 3 curve over any finite field of characteristic 3 whose number of rational points stays within a fixed distance from the Hasse-Weil-Serre upper bound. We…

Number Theory · Mathematics 2007-05-23 Roland Auer , Jaap Top

In this paper we construct complex contact structures on $\mathbb{C}^{2n+1}$ for any $n\ge 1$ with the property that every holomorphic Legendrian map $\mathbb{C}\to \mathbb{C}^{2n+1}$ is constant. In particular, these contact structures are…

Complex Variables · Mathematics 2018-05-11 Franc Forstneric

Motivated by Legendrian curve shortening flows in $\mathbb{R}^{3}$, we study the curve shortening flow of figure-eight curves in the plane. We show that, under some symmetry and curvature conditions, a figure-eight curve will shrink to a…

Differential Geometry · Mathematics 2015-08-06 Gregory Drugan , Weiyong He , Micah W. Warren

We introduce and study \emph{contact whirl curves} in three-dimensional Lorentzian contact manifolds, with emphasis on the Sasakian setting. This notion refines the concept of whirl curves by encoding the interaction between the adapted…

Differential Geometry · Mathematics 2026-05-13 Luis E. Portilla P. , Guerrero M. Hector

In this note we deal with rational curves in P^3 which are images of a line by means of a finite sequence of cubo-cubic Cremona transformations. We prove that these curves can always be obtained applying to the line a sequence of such…

Algebraic Geometry · Mathematics 2007-05-23 Antonio Laface , Luca Ugaglia

We construct a moduli space for Legendrian curves singularities which are contactomorphic-equivalent and equisingular through a contact analogue of the Kodaira-Spencer map for curve singularities. We focus on the specific case of Legendrian…

Algebraic Geometry · Mathematics 2019-02-25 Marco Silva Mendes , Orlando Neto

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

I prove that every smooth legendrian variety generated by quadrics is a homogeneous variety and further I give a list of all such legendrian varieties. A review of the subject is included, illustrated by examples. Another result is that no…

Algebraic Geometry · Mathematics 2007-05-23 Jaroslaw Buczynski

Given a singular projective variety in some projective space, we characterize the smooth curves contracted by the Gauss map in terms of normal bundles. As a consequence, we show that if the variety is normal, then a contracted line always…

Algebraic Geometry · Mathematics 2022-06-14 Lei Song

In the unit cotangent bundle of $\mathbb{R}^3$, we consider loops of Legendrian tori arising as families of the unit conormal bundles of smooth knots in $\mathbb{R}^3$. In this paper, using the cord algebra of knots, we give a topological…

Symplectic Geometry · Mathematics 2026-02-13 Yukihiro Okamoto , Marián Poppr

If $C \subset P^3_k$ is an integral curve and $k$ an algebraically closed field of characteristic 0, it is known that the points of the general plane section $C \cap H$ of $C$ are in uniform position. From this it follows easily that the…

Algebraic Geometry · Mathematics 2010-09-22 Paola Bonacini

In the present paper, we define and study $C$-parallel and $C$-proper slant curves of $S$-manifolds. We prove that a curve $\gamma $ in an $S$-manifold of order $r\geq 3,$ under certain conditions, is $C$-parallel or $C$-parallel in the…

General Mathematics · Mathematics 2020-04-14 Şaban Güvenç , Cihan Özgür

Laudal's Lemma states that if $C$ is a curve of degree $d > s^2 + 1$ in $\mathbb P^3$ over an algebraically closed field of characteristic 0 such that its plane section is contained in an irreducible curve of degree s, then $C$ lies on a…

Algebraic Geometry · Mathematics 2010-09-22 Paola Bonacini

Suppose $K$ is a knot in a 3-manifold $Y$, and that $Y$ admits a pair of distinct contact structures. Assume that $K$ has Legendrian representatives in each of these contact structures, such that the corresponding Thurston-Bennequin…

Geometric Topology · Mathematics 2024-04-11 Shunyu Wan

We give a construction of embedded contact homology (ECH) for a contact $3$-manifold $Y$ with convex sutured boundary and a pair of Legendrians $\Lambda_+$ and $\Lambda_-$ contained in $\partial Y$ satisfying an exactness condition. The…

Symplectic Geometry · Mathematics 2023-02-16 Julian Chaidez , Oliver Edtmair , Luya Wang , Yuan Yao , Ziwen Zhao