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Related papers: On large partial ovoids of symplectic and Hermitia…

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Two results are obtained that give upper bounds on partial spreads and partial ovoids respectively. The first result is that the size of a partial spread of the Hermitian polar space $\mathsf{H}(3, q^2)$ is at most $\left(\frac{2p^3+p}{3}…

Combinatorics · Mathematics 2020-02-21 Ferdinand Ihringer , Peter Sin , Qing Xiang

We provide new proofs for the non-existence of ovoids in hyperbolic spaces of rank at least four in even characteristic, and for the Hermitian polar space $\mathsf{H}(5, 4)$. We also improve the results of A. Klein on the non-existence of…

Combinatorics · Mathematics 2015-09-17 John Bamberg , Jan De Beule , Ferdinand Ihringer

In this paper we are concerned with $m$-ovoids of the symplectic polar space ${\cal W}(2n+1, q)$, $q$ even. In particular we show the existence of an elliptic quadric of ${\rm PG}(2n+1, q)$ not polarizing to ${\cal W}(2n+1, q)$ forming a…

Combinatorics · Mathematics 2022-07-05 Michela Ceria , Francesco Pavese

A {\em maximal partial ovoid} of a generalized quadrangle is a maximal set of points no two of which are collinear. The problem of determining the smallest size of a maximal partial ovoid in quadrangles has been extensively studied in the…

Metric Geometry · Mathematics 2013-08-09 Jeroen Schillewaert , Jacques Verstraete

The size of the largest Erd\H os-Ko-Rado set of generators in the finite classical polar space is known for all polar spaces except for $H(2d-1,q^2)$ when $d\ge 5$ is odd. We improve the known upper bound in this remaining case by using a…

Combinatorics · Mathematics 2015-02-19 Klaus Metsch

In this paper, we develop a new method for constructing $m$-ovoids in the symplectic polar space $\W(2r-1,\q)$ from some strongly regular Cayley graphs in \cite{Brouwer1999Journal}. Using this method, we obtain many new $m$-ovoids which can…

Combinatorics · Mathematics 2019-09-18 Tao Feng , Ye Wang , Qing Xiang

In [9], the codewords of small weight in the dual code of the code of points and lines of Q(4, q) are characterised. Inspired by this result, using geometrical arguments, we characterise the codewords of small weight in the dual code of the…

Combinatorics · Mathematics 2012-01-17 Valentina Pepe , Leo Storme , Geertrui Van de Voorde

An ovoid of a dual polar space is a point set meeting every line in exactly one point. For the symplectic dual polar space DW(6,q), Cooperstein and Pasini have recently proved no ovoid exists if q is odd. Earlier, Shult has proved the same…

Algebraic Geometry · Mathematics 2007-05-23 Harm Pralle

In this paper, we complete the classification of transitive ovoids of finite Hermitian polar spaces.

Combinatorics · Mathematics 2020-11-19 Tao Feng , Weicong Li

In this paper we develop non-existence results for $m$-ovoids in the classical polar spaces $Q^-(2r+1,q), W(2r-1,q)$ and $H(2r,q^2)$ for $r>2$. In [4] a lower bound on $m$ for the existence of $m$-ovoids of $H(4,q^2)$ is found by using the…

Combinatorics · Mathematics 2024-02-21 Jan De Beule , Jonathan Mannaert , Valentino Smaldore

We use the representation $T_2(O)$ for $\q(4,q)$ to show that maximal partial ovoids of $\q(4,q)$ of size $q^2-1$, $q=p^h$, $p$ odd prime, $h > 1$, do not exist. Although this was known before, we give a slightly alternative proof, also…

Combinatorics · Mathematics 2012-03-09 Jan De Beule

We study certain physically-relevant subgeometries of binary symplectic polar spaces $W(2N-1,2)$ of small rank $N$, when the points of these spaces canonically encode $N$-qubit observables. Key characteristics of a subspace of such a space…

Quantum Physics · Physics 2021-09-20 Metod Saniga , Henri de Boutray , Frederic Holweck , Alain Giorgetti

The Desarguesian ovoids in the orthogonal polar space $Q^+(7,q)$ with $q$ even have first been introduced by Kantor by examining the $8$-dimensional absolutely irreducible modular representations of $\text{PGL}(2,q^3)$. We investigate this…

Information Theory · Computer Science 2022-08-30 Tao Feng , Michael Kiermaier , Peixian Lin , Kai-Uwe Schmidt

An $m$-ovoid of a finite polar space $\mathcal{P}$ is a set $\mathcal{O}$ of points such that every maximal subspace of $\mathcal{P}$ contains exactly $m$ points of $\mathcal{O}$. In the case when $\mathcal{P}$ is an elliptic quadric…

Combinatorics · Mathematics 2021-11-16 Alexander L. Gavrilyuk , Klaus Metsch , Francesco Pavese

We present a description of maximal partial ovoids of size $q^2-1$ of the parabolic quadric $\q(4,q)$ as sharply transitive subsets of $\SL(2,q)$ and show their connection with spread sets. This representation leads to an elegant explicit…

Combinatorics · Mathematics 2012-02-02 Kris Coolsaet , Jan De Beule , Alessandro Siciliano

We investigate what we call generalized ovoids, that is families of totally isotropic subspaces of finite classical polar spaces such that each maximal totally isotropic subspace contains precisely one member of that family. This is a…

Combinatorics · Mathematics 2024-01-22 Jozefien D'haeseleer , Ferdinand Ihringer , Kai-Uwe Schmidt

We study moduli spaces of O'Grady's ten-dimensional irreducible symplectic manifolds. These moduli spaces are covers of modular varieties of dimension 21, namely quotients of hermitian symmetric domains by a suitable arithmetic group. The…

Algebraic Geometry · Mathematics 2010-05-27 V. Gritsenko , K. Hulek , G. K. Sankaran

We give sufficient conditions for self-orthogonality with respect to symplectic, Euclidean and Hermitian inner products of a wide family of quasi-cyclic codes of index two. We provide lower bounds for the symplectic weight and the minimum…

Information Theory · Computer Science 2019-02-15 Carlos Galindo , Fernando Hernando , Ryutaroh Matsumoto

We provide polynomial upper bounds for the minimal sizes of distal cell decompositions in several kinds of distal structures, particularly weakly $o$-minimal and $P$-minimal structures. The bound in general weakly $o$-minimal structures…

Logic · Mathematics 2026-02-11 Aaron Anderson

In [1], a new quasi-Hermitian variety $\mathcal{H}_\varepsilon^r$ in $\mathrm{PG}(r, q^2)$, with $q = 2^e$ and $e \geq 3$ an odd integer, was constructed. The variety depends on a primitive element $\varepsilon$ of the underlying field…

Combinatorics · Mathematics 2025-08-07 Angela Aguglia , Alessandro Montinaro
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