Turán, involution and shifting
نویسندگان
چکیده
منابع مشابه
Ultra and Involution Ideals in $BCK$-algebras
In this paper, we define the notions of ultra and involution ideals in $BCK$-algebras. Then we get the relation among them and other ideals as (positive) implicative, associative, commutative and prime ideals. Specially, we show that in a bounded implicative $BCK$-algebra, any involution ideal is a positive implicative ideal and in a bounded positive implicative lower $BCK$-semilattice, the not...
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Our aim in this note is to make some conjectures about extremal densities of daisy-free families, where a ‘daisy’ is a certain hypergraph. These questions turn out to be related to some Turán problems in the hypercube, but they are also natural in their own right. We start by giving the daisy conjectures, and some related problems, and shall then go on to describe the connection with vertex-Tur...
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For a fixed graph H, we define the rainbow Turán number ex∗(n,H) to be the maximum number of edges in a graph on n vertices that has a proper edge-colouring with no rainbow H. Recall that the (ordinary) Turán number ex(n,H) is the maximum number of edges in a graph on n vertices that does not contain a copy of H. For any non-bipartite H we show that ex∗(n,H) = (1+o(1))ex(n,H), and if H is colou...
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Let Hð3;1Þ denote the complete bipartite graph K3;3 with an edge deleted. For given graphs G and F , the Turán numbers exðG; FÞ denote the maximum number of edges in a subgraph of G containing no copy of F . We prove that exðKn;n;Hð3; 1ÞÞ ð4= ffiffiffi 7 p n þOðnÞ 1:5119n þOðnÞ and that exðKn;Hð3; 1ÞÞ ð1=5Þ ffiffiffiffiffi 15 p n þOðnÞ 0:7746n þ OðnÞ, which improve earlier results of Mubayi-Wes...
متن کاملℓ-Degree Turán Density
Access to the published version may require subscription. Abstract. Let Hn be a k-graph on n vertices. For 0 ≤ ℓ < k and an ℓ-subset T of V (Hn), define the degree deg(T) of T to be the number of (k − ℓ)-subsets S such that S ∪ T is an edge in Hn. Let the minimum ℓ-degree of Hn be δ ℓ (Hn) = min{deg(T) : T ⊆ V (Hn) and |T | = ℓ}. Given a family F of k-graphs, the ℓ-degree Turán number ex ℓ (n, ...
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ژورنال
عنوان ژورنال: Algebraic Combinatorics
سال: 2019
ISSN: 2589-5486
DOI: 10.5802/alco.30