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In this paper we establish an improved bound for the number of incidences between a set $P$ of $m$ points and a set $H$ of $n$ planes in $\mathbb R^3$, provided that the points lie on a two-dimensional nonlinear irreducible algebraic…

组合数学 · 数学 2017-05-31 Micha Sharir , Noam Solomon

We establish an improved upper bound for the number of incidences between m points and n circles in three dimensions. The previous best known bound, originally established for the planar case and later extended to any dimension $\ge 2$, is…

组合数学 · 数学 2019-02-20 Micha Sharir , Adam Sheffer , Joshua Zahl

A lower bound on the minimum degree of the plane algebraic curves containing every point in a large point-set $K$ of the Desarguesian plane $PG(2,q)$ is obtained. The case where $K$ is a maximal $(k,n)$-arc is considered to greater extent.

组合数学 · 数学 2009-07-18 A. Aguglia , L. Giuzzi , G. Korchmaros

A widely believed conjecture predicts that curves of bounded geometric genus lying on a variety of general type form a bounded family. One may even ask whether the canonical degree of a curve $C$ in a variety of general type is bounded from…

代数几何 · 数学 2018-09-25 Pascal Autissier , Antoine Chambert-Loir , Carlo Gasbarri

We are interested to bound from below the number of distinct dot products determined by a finite set of points $P$ in the Euclidean plane. In this paper, we build on the work of B. Hanson, O. Roche-Newton, and S. Senger, to obtain the…

组合数学 · 数学 2025-02-19 Michalis Kokkinos

In this revised form, the proof of the principal lemma has been simplified and the main theorem has been extended to all characteristics for those varieties which are smooth in codimension one. This principal theorem essentially says the…

alg-geom · 数学 2009-09-25 J. Alexander , A. Hirschowitz

Using degeneration to scrolls, we give an easy proof of non-existence of curves of low genera on general surfaces in P3 of degree d >=5. We show, along the same lines, boundedness of families of curves of small enough genera on general…

代数几何 · 数学 2011-03-16 Ciro Ciliberto , Mikhail Zaidenberg

The \emph{canonical degree} of a curve $C$ on a surface $X$ is $K_X\cdot C$. Our main result, is that on a surface of general type there are only finitely many curves with negative self--intersection and sufficiently large canonical degree.…

代数几何 · 数学 2014-07-01 Ciro Ciliberto , Xavier Roulleau

In this paper, we study the curvature properties of random complex plane curves. We bound from below the probability that a uniform proportion of the area of a random complex degree $d$ plane curve has a curvature smaller than $-d/8$. Our…

代数几何 · 数学 2024-02-20 Michele Ancona , Damien Gayet

We give an asymptotic lower bound on the number of field extensions generated by algebraic points on superelliptic curves over $\mathbb{Q}$ with fixed degree $n$ and discriminant bounded by $X$. For $C$ a fixed such curve given by an affine…

数论 · 数学 2025-09-17 Lea Beneish , Christopher Keyes

We address the problem of the maximal finite number of real points of a real algebraic curve (of a given degree and, sometimes, genus) in the projective plane. We improve the known upper and lower bounds and construct close to optimal…

代数几何 · 数学 2019-09-13 Erwan Brugallé , Alex Degtyarev , Ilia Itenberg , Frédéric Mangolte

A well-known conjecture of Erd\H{o}s and S\'os states that every graph with average degree exceeding $m-1$ contains every tree with $m$ edges as a subgraph. We propose a variant of this conjecture, which states that every graph of maximum…

组合数学 · 数学 2020-12-14 Frédéric Havet , Bruce Reed , Maya Stein , David R. Wood

First we give a sharp upper bound for the cardinal $m$ of a minimal set of generators for the module of Jacobian syzygies of a complex projective reduced plane curve $C$. Next we discuss the sharpness of an upper bound, given by A. du…

代数几何 · 数学 2019-04-30 Alexandru Dimca , Gabriel Sticlaru

Boros and Furedi (for d=2) and Barany (for abritrary d) proved that there exists a positive real number c_d such that for every set P of n points in R^d in general position, there exists a point of R^d contained in at least c_d…

组合数学 · 数学 2012-03-22 Daniel Kral , Lukas Mach , Jean-Sebastien Sereni

We prove: if $d/m < 2280/721$, there is no curve of degree $d$ passing through $n = 10$ general points with multiplicity $m$ in $\bf{P}^2$. Similar results are given for other special values of $n$. Our bounds can be naturally written as…

代数几何 · 数学 2012-11-28 Ivan Petrakiev

For each $n$, let $\text{RD}(n)$ denote the minimum $d$ for which there exists a formula for the general polynomial of degree $n$ in algebraic functions of at most $d$ variables. In 1945, Segre called for a better understanding of the large…

代数几何 · 数学 2021-07-20 Alexander J. Sutherland

In this article, we study the generalized Poincare problem from the opposite perspective, by establishing lower bounds on the degree of the vector field in terms of invariants of the variety.

交换代数 · 数学 2024-03-18 Marc Chardin , S. Hamid Hassanzadeh , Claudia Polini , Aron Simis , Bernd Ulrich

This is an addendum to the paper of Braun and Fl{\o}ystad ([BF]) on the bound for the degree of a smooth surface in $\pfour$ not of general type. Using their construction and the regularity of curves in $\pthree$, one may lower the bound a…

alg-geom · 数学 2015-06-30 Michele Cook

In this paper we give a new proof of the fact that for all pairs of positive integers (d, m) with d/m < 117/37, the linear system of plane curves of degree d with ten general base points of multiplicity m is empty.

代数几何 · 数学 2009-10-08 Ciro Ciliberto , Olivia Dumitrescu , Rick Miranda , Joaquim Roé

For every integer $k \geq 3$ we construct a $k$-gonal curve $C$ along with a very ample divisor of degree $2g + k - 1$ (where $g$ is the genus of $C$) to which the vanishing statement from the Green-Lazarsfeld gonality conjecture does not…

代数几何 · 数学 2017-04-12 Wouter Castryck