An extension of the direction problem
Autor: | Marcella Takáts, Péter Sziklai |
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Rok vydání: | 2012 |
Předmět: |
Discrete mathematics
Quadric Finite affine space 05B25 51E20 51D20 Theoretical Computer Science Combinatorics Affine coordinate system Affine geometry Affine geometry of curves Hyperplane Direction Affine hull Affine group Affine space Mathematics - Combinatorics Discrete Mathematics and Combinatorics Mathematics |
Zdroj: | Discrete Mathematics. 312(12-13):2083-2087 |
ISSN: | 0012-365X |
DOI: | 10.1016/j.disc.2012.02.021 |
Popis: | Let $U$ be a point set in the $n$-dimensional affine space ${\rm AG}(n,q)$ over the finite field of $q$ elements and $0\leq k\leq n-2$. In this paper we extend the definition of directions determined by $U$: a $k$-dimensional subspace $S_k$ at infinity is determined by $U$ if there is an affine $(k+1)$-dimensional subspace $T_{k+1}$ through $S_k$ such that $U\cap T_{k+1}$ spans $T_{k+1}$. We examine the extremal case $|U|=q^{n-1}$, and classify point sets NOT determining every $k$-subspace in certain cases. Comment: 7 pages. NOTICE: this is the author's version of a work that was accepted for publication in Discr. Math. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication |
Databáze: | OpenAIRE |
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