English
Related papers

Related papers: Incidences between quadratic subspaces over finite…

200 papers

Let $k$ be a field of characteristic not 2 or 3. We establish polynomial lower bounds on the ambient dimension $N$ for an intersection $X\subset\mathbb{P}^N$ of quadrics, cubics and quartics to have a dense collection of solvable points,…

Algebraic Geometry · Mathematics 2025-08-04 Claudio Gómez-Gonzáles , Jesse Wolfson

$q$-analogues of quantities in mathematics involve perturbations of classical quantities using the parameter $q$, and revert to the original quantities when $q$ goes $1$. An important example is the $q$-analogues of binomial coefficients…

Combinatorics · Mathematics 2021-05-18 Semin Yoo

Let $p_1,\ldots,p_n$ be a set of points in the unit square and let $T_1,\ldots,T_n$ be a set of $\delta$-tubes such that $T_j$ passes through $p_j$. We prove a lower bound for the number of incidences between the points and tubes under a…

Combinatorics · Mathematics 2025-03-19 Alex Cohen , Cosmin Pohoata , Dmitrii Zakharov

We prove a new, tight upper bound on the number of incidences between points and hyperplanes in Euclidean d-space. Given n points, of which k are colored red, there are O_d(m^{2/3}k^{2/3}n^{(d-2)/3} + kn^{d-2} + m) incidences between the k…

Combinatorics · Mathematics 2012-01-10 Ben D. Lund , George B. Purdy , Justin W. Smith

We present a direct and fairly simple proof of the following incidence bound: Let $P$ be a set of $m$ points and $L$ a set of $n$ lines in ${\mathbb R}^d$, for $d\ge 3$, which lie in a common algebraic two-dimensional surface of degree $D$…

Algebraic Geometry · Mathematics 2015-06-03 Micha Sharir , Noam Solomon

A $t$-intersecting constant dimension subspace code $C$ is a set of $k$-dimensional subspaces in a projective space PG(n,q), where distinct subspaces intersect in a $t$-dimensional subspace. A classical example of such a code is the…

Combinatorics · Mathematics 2021-05-24 Aart Blokhuis , Maarten De Boeck , Jozefien D'haeseleer

The point-plane incidence theorem states that the number of incidences between $n$ points and $m\geq n$ planes in the projective three-space over a field $F$, is $$O\left(m\sqrt{n}+ m k\right),$$ where $k$ is the maximum number of collinear…

Combinatorics · Mathematics 2018-06-12 Misha Rudnev

Let $Q$ be an ideal (downward-closed set) in the lattice of linear subspaces of $(\mathbb F_q)^n$, ordered by inclusion. For $0 \le k \le n$, let $\mu_k(Q)$ denote the fraction of $k$-dimensional subspaces that belong to $Q$. We show that…

Combinatorics · Mathematics 2019-10-03 Benjamin Rossman

In this paper, we first define a non-degenerate symmetric bilinear form on Fq^4. Then we get an incidence matrix G of Fq^4 by the bilinear form. By its corresponding quadratic form Q, the lines of Fq^4 are classified as isotropic and…

Number Theory · Mathematics 2013-04-24 Chunlei Liu , Haode Yan

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…

Combinatorics · Mathematics 2017-05-31 Micha Sharir , Noam Solomon

In this paper we find a new lower bound on the number of imaginary quadratic extensions of the function field $\mathbb{F}_{q}(x)$ whose class groups have elements of a fixed odd order. More precisely, for $q$, a power of an odd prime, and…

Number Theory · Mathematics 2011-02-21 Pradipto Banerjee , Srinivas Kotyada

A subspace of a finite field is called a Sidon space if the product of any two of its nonzero elements is unique up to a scalar multiplier from the base field. Sidon spaces, introduced by Roth et al. (IEEE Trans Inf Theory 64(6): 4412-4422,…

Discrete Mathematics · Computer Science 2023-05-26 Shuhui Yu , Lijun Ji

Given a hypergraph $H$ with $m$ hyperedges and a set $Q$ of $m$ \emph{pinning subspaces}, i.e.\ globally fixed subspaces in Euclidean space $\mathbb{R}^d$, a \emph{pinned subspace-incidence system} is the pair $(H, Q)$, with the constraint…

Computational Geometry · Computer Science 2016-03-15 Meera Sitharam , Mohamad Tarifi , Menghan Wang

Let $E \subseteq \mathbb{F}_q^2$ be a set in the 2-dimensional vector space over a finite field with $q$ elements. We prove an identity for the second moment of its incidence function and deduce a variety of existing results from the…

Combinatorics · Mathematics 2016-11-17 Brendan Murphy , Giorgis Petridis

In this paper, we derive a tight upper bound for the size of an intersecting $k$-Sperner family of subspaces of the $n$-dimensional vector space $\mathbb{F}_{q}^{n}$ over finite field $\mathbb{F}_{q}$ which gives a $q$-analogue of the…

Combinatorics · Mathematics 2024-05-01 Jiuqiang Liu , Guihai Yu , Lihua Feng , Yongtao Li

In this paper we introduce a unified approach to deal with incidence problems between points and varieties over finite fields. More precisely, we prove that the number of incidences $I(\mathcal{P}, \mathcal{V})$ between a set $\mathcal{P}$…

Combinatorics · Mathematics 2016-01-05 Nguyen Duy Phuong , Thang Pham , Nguyen Minh Sang , Claudiu Valculescu , Le Anh Vinh

We present a polynomial partitioning theorem for finite sets of points in the real locus of an irreducible complex algebraic variety of codimension at most two. This result generalizes the polynomial partitioning theorem on the Euclidean…

Algebraic Geometry · Mathematics 2015-09-22 Saugata Basu , Martin Sombra

We present a technique for deriving lower bounds for incidences with hypersurfaces in ${\mathbb R}^d$ with $d\ge 4$. These bounds apply to a large variety of hypersurfaces, such as hyperplanes, hyperspheres, paraboloids, and hypersurfaces…

Combinatorics · Mathematics 2016-10-05 Adam Sheffer

There are many specific results, spread over the literature, regarding the dualisation of quadrics in projective spaces and quadratic forms on vector spaces. In the present work we aim at generalising and unifying some of these. We start…

Algebraic Geometry · Mathematics 2025-07-01 Hans Havlicek

Let $p$ denote the characteristic of ${\mathbb F}_q$, the finite field with $q$ elements. We prove that if $q$ is odd then an arc of size $q+2-t$ in the projective plane over ${\mathbb F}_q$, which is not contained in a conic, is contained…

Combinatorics · Mathematics 2018-04-05 Simeon Ball , Michel Lavrauw