Zobrazeno 1 - 10
of 771
pro vyhledávání: '"05B05"'
Autor:
Stroppel, Markus Johannes
We prove the statement in the title: if a (finite) unital admits all translations and contains no O'Nan configurations then the unital is classical, i.e., isomorphic to the Hermitian unital of the same order.
Externí odkaz:
http://arxiv.org/abs/2410.08605
A graph $G$ of constant link $L$ is a graph in which the neighborhood of any vertex induces a graph isomorphic to $L$. Given two different graphs, $H$ and $G$, the induced Tur\'an number ${\rm ex}(n; H, G{\rm -ind})$ is defined as the maximum number
Externí odkaz:
http://arxiv.org/abs/2409.12875
Autor:
Saeidi, Amin
In this paper, we present a method for constructing point primitive block transitive $t$-designs invariant under finite groups. Furthermore, we demonstrate that every point and block primitive $G$-invariant design can be generated using this method.
Externí odkaz:
http://arxiv.org/abs/2409.09730
In this article, we investigate symmetric designs admitting a flag-transitive and point-primitive affine automorphism group. We prove that if an automorphism group $G$ of a symmetric $(v,k,\lambda)$ design with $\lambda$ prime is point-primitive of a
Externí odkaz:
http://arxiv.org/abs/2409.04790
Autor:
Stömmer, Ralph
Stefan Mandel is the man who won the lottery 14 times. He never disclosed the recipe he called combinatorial condensation, which enabled him to hit the Romanian lottery jackpot in the early phase of his betting career. Combinatorial condensation is f
Externí odkaz:
http://arxiv.org/abs/2408.06857
Autor:
McCulloch, Ryan
Publikováno v:
Innovations in Incidence Geometry: Algebraic, Topological and Combinatorial 2024
In this note we establish a 1-to-1 correspondence between the class of generalized quadrangles with ovoids and the class of balanced incomplete block designs that posses a non-triangular local resolution system and have the appropriate parameters. We
Externí odkaz:
http://arxiv.org/abs/2408.00887
For a positive integer $n$, a graph with at least $n$ vertices is $n$-existentially closed or simply $n$-e.c. if for any set of vertices $S$ of size $n$ and any set $T\subseteq S$, there is a vertex $x\not\in S$ adjacent to each vertex of $T$ and no
Externí odkaz:
http://arxiv.org/abs/2407.06054
Autor:
Stinson, Douglas R.
We study two types of nestings of balanced incomplete block designs (BIBDs). In both types of nesting, we wish to add a point (the nested point) to every block of a $(v,k,\lambda)$-BIBD in such a way that we end up with a partial $(w,k+1,\lambda+1)$-
Externí odkaz:
http://arxiv.org/abs/2405.12820
Autor:
Krčadinac, Vedran
We give the first example of a mosaic of three combinatorial designs with distinct parameters $2$-$(13,3,1)$, $2$-$(13,4,2)$, and $2$-$(13,6,5)$. Furthermore, we give examples of mosaics of $2$-$(9,3,2)$ designs that are not resolvable, thereby answe
Externí odkaz:
http://arxiv.org/abs/2405.12672
In 1982, Cameron and Liebler investigated certain "special sets of lines" in PG(3,q), and gave several equivalent characterizations. Due to their interesting geometric and algebraic properties, these "Cameron-Liebler line classes" got a lot of attent
Externí odkaz:
http://arxiv.org/abs/2405.07572