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Related papers: Blocking sets from a union of plane curves

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We study arrangements of intervals in $\mathbb{R}^2$ for which many pairs form trapezoids. We show that any set of intervals forming many trapezoids must have underlying algebraic structure, which we characterise. This leads to some…

Combinatorics · Mathematics 2020-05-20 Daniel Di Benedetto , Jozsef Solymosi , Ethan White

Blocking semiovals and the determination of their (minimum) sizes constitute one of the central research topics in finite projective geometry. In this article we introduce the concept of blocking set with the $r_\infty$-property in a finite…

Combinatorics · Mathematics 2025-07-31 Marilena Crupi , Antonino Ficarra

The decomposition group of an irreducible plane curve $X\subset\mathbb P^2$ is the subgroup $\mathrm{Dec}(X)\subset\mathrm{Bir}(\mathbb P^2)$ of birational maps which restrict to a birational map of $X$. We show that $\mathrm{Dec}(X)$ is…

Algebraic Geometry · Mathematics 2017-06-09 Tom Ducat , Isac Hedén , Susanna Zimmermann

We study plane algebraic curves defined over a field k of arbitrary characteristic as coverings of the the projective line and the problem of enumerating branched coverings of $\mathbb{P}^{1}$ by using combinatorial methods.

Algebraic Geometry · Mathematics 2012-09-20 Alberto Besana , Cristina Martinez

Let $n$ be a positive integer. Denote by $\mathrm{PG}(n,q)$ the $n$-dimensional projective space over the finite field $\mathbb{F}_q$ of order $q$. A blocking set in $\mathrm{PG}(n,q)$ is a set of points that has non-empty intersection with…

Group Theory · Mathematics 2009-01-14 Alireza Abdollahi

This paper studies {\em strong blocking sets} in the $N$-dimensional finite projective space $\mathrm{PG}(N,q)$. We first show that certain unions of blocking sets cannot form strong blocking sets, which leads to a new lower bound on the…

Combinatorics · Mathematics 2024-02-13 Stefano Lia , Geertrui Van de Voorde

In this paper we give some basic results on blocking sets on minimum size for a finite chain geometry.

Combinatorics · Mathematics 2013-04-05 Andrea Blunck , Hans Havlicek , Corrado Zanella

In this paper, we study the deformations of curves in the projective 3-space $\mathbb P^3$ (space curves), one of the most classically studied objects in algebraic geometry. We prove a conjecture due to J. O. Kleppe (in fact, a version…

Algebraic Geometry · Mathematics 2022-05-31 Hirokazu Nasu

We examine the maximum dimension of a linear system of plane cubic curves whose $\mathbb{F}_q$-members are all geometrically irreducible. Computational evidence suggests that such a system has a maximum (projective) dimension of $3$. As a…

Algebraic Geometry · Mathematics 2024-12-23 Shamil Asgarli , Dragos Ghioca

In this note we will provide proofs for the various statements that have been made in the literature about blocking sets of index three. Our aim is to clarify what is known about the characterization of these sets. Specifically, we provide…

Combinatorics · Mathematics 2012-06-05 William E. Cherowitzo , Leanne D. Holder

We show that a set of $n$ algebraic plane curves of constant maximum degree can be cut into $O(n^{3/2}\operatorname{polylog} n)$ Jordan arcs, so that each pair of arcs intersect at most once, i.e., they form a collection of pseudo-segments.…

Combinatorics · Mathematics 2018-07-10 Micha Sharir , Joshua Zahl

This paper considers the task of connecting points on a piece of paper by drawing a curve between each pair of them. Under mild assumptions, we prove that many pairwise disjoint curves are unavoidable if either of the following rules is…

Computational Geometry · Computer Science 2026-03-06 Alexandra Weinberger , Ji Zeng

Using the Semple bundle construction, we derive an intersection-theoretic formula for the number of simultaneous contacts of specified orders between members of a generic family of degree $d$ plane curves and finitely many fixed curves. The…

alg-geom · Mathematics 2008-02-03 Susan Jane Colley , Gary Kennedy

A plane curve $C$ in $\mathbb{P}^2$ defined over $\mathbb{F}_q$ is called plane-filling if $C$ contains every $\mathbb{F}_q$-point of $\mathbb{P}^2$. Homma and Kim, building on the work of Tallini, proved that the minimum degree of a smooth…

Algebraic Geometry · Mathematics 2023-07-07 Shamil Asgarli , Dragos Ghioca

In this paper we study a construction of algebraic curves from combinatorial data. In the study of algebraic curves through degeneration, graphs usually appear as the dual intersection graph of the central fiber. Properties of such graphs…

Algebraic Geometry · Mathematics 2017-05-03 Takeo Nishinou

The purpose of this note is to prove that there is an algebraic stack U parameterizing all curves. The curves that appear in the algebraic stack U are allowed to be arbitrarily singular, non-reduced, disconnected, and reducible. We also…

Algebraic Geometry · Mathematics 2010-11-30 Jack Hall

Based on the fact that projective monomial curves in the plane are complete intersections, we give an effective inductive method for creating infinitely many monomial curves in the projective $n$-space that are set theoretic complete…

Commutative Algebra · Mathematics 2015-12-09 Tran Hoai Ngoc Nhan , Mesut Şahin

We propose reducible algebraic curves as a mechanism to construct Partial MDS (PMDS) codes geometrically. We obtain new general existence results, new explicit constructions and improved estimates on the smallest field sizes over which such…

Information Theory · Computer Science 2020-07-30 Tristram Bogart , Anna-Lena Horlemann-Trautmann , David Karpuk , Alessandro Neri , Mauricio Velasco

Regular algebraic surfaces isogenous to a higher product of curves can be obtained from finite groups with ramification structures. We find unmixed ramification structures for finite groups constructed as p-quotients of particular infinite…

Group Theory · Mathematics 2011-09-29 Nathan Barker , Nigel Boston , Norbert Peyerimhoff , Alina Vdovina

Given two points in the plane, a set of obstacles defined by closed curves, and an integer $k$, does there exist a path between the two designated points intersecting at most $k$ of the obstacles? This is a fundamental and well-studied…

Data Structures and Algorithms · Computer Science 2020-02-05 Eduard Eiben , Daniel Lokshtanov