Results 41 to 50 of about 995,571 (241)
Excluded subposets in the Boolean lattice [PDF]
We are looking for the maximum number of subsets of an n-element set not containing 4 distinct subsets satisfying $A ⊂B, C ⊂B, C ⊂D$. It is proved that this number is at least the number of the $\lfloor \frac{n }{ 2}\rfloor$ -element sets times $1+\frac ...
Gyula O.H. Katona
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An Extremal Problem for Finite Lattices
For a fixed M x N integer lattice L(M,N), we consider the maximum size of a subset A of L(M,N) which contains no squares of prescribed side lengths k(1),...,k(t).
John Goldwasser+2 more
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Positional games are a branch of combinatorics, researching a variety of two-player games, ranging from popular recreational games such as Tic-Tac-Toe and Hex, to purely abstract games played on graphs and hypergraphs.
Krivelevich, Michael
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A characterization of extremal graphs with no matching-cut [PDF]
A graph is called (matching-)immune if it has no edge cut that is also a matching. Farley and Proskurowski proved that for all immune graphs $G=(V,E)$, $|E|≥\lceil 3(|V|-1)/2\rceil$ , and constructed a large class of immune graphs that attain this lower ...
Paul Bonsma
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Extremal properties of (epi)Sturmian sequences and distribution modulo 1 [PDF]
Starting from a study of Y. Bugeaud and A. Dubickas (2005) on a question in distribution of real numbers modulo 1 via combinatorics on words, we survey some combinatorial properties of (epi)Sturmian sequences and distribution modulo 1 in connection to ...
Allouche, Jean-Paul, Glen, Amy
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List graphs and distance-consistent node labelings
In this paper we consider node labelings c of an undirected connected graph G = (V, E) with labels {1, 2, ..., ∣V∣}, which induce a list distance c(u, v) = ∣c(v) − c(u)∣ besides the usual graph distance d(u, v).
Håkan Lennerstad, Mattias Eriksson
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An extremal problem on trees and database theory [PDF]
We consider an extremal problem on labelled directed trees and applications to database theory. Among others, we will show explicit keysystems on an underlying set of size $n$, that cannot be represented by a database of less than $2^{n(1-c\cdot \log ...
Gyula O.H. Katona, Krisztián Tichler
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Recent Trends in Combinatorics [PDF]
Section 1: Extremal and Probabilistic Combinatorics -- Problems Related to Graph Indices in Trees -- The edit distance in graphs: methods, results and generalizations -- Repetitions in graphs and sequences -- On Some Extremal Problems for Cycles in ...
Beveridge, Andrew+5 more
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Donaldson-Thomas invariants, torus knots, and lattice paths [PDF]
In this paper we find and explore the correspondence between quivers, torus knots, and combinatorics of counting paths. Our first result pertains to quiver representation theory -- we find explicit formulae for classical generating functions and ...
Panfil, Miłosz+2 more
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Hypergraphs with infinitely many extremal constructions
Hypergraphs with infinitely many extremal constructions, Discrete Analysis 2023:18, 34 pp. A fundamental result in extremal graph theory, Turán's theorem, states that the maximal number of edges of a graph with $n$ vertices that does not contain a ...
Jianfeng Hou+4 more
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