Results 1 to 10 of about 14,274 (218)
The topological symmetric orbifold
We analyze topological orbifold conformal field theories on the symmetric product of a complex surface M. By exploiting the mathematics literature we show that a canonical quotient of the operator ring has structure constants given by Hurwitz numbers ...
Songyuan Li, Jan Troost
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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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A question of Bukh on sums of dilates
A question of Bukh on sums of dilates, Discrete Analysis 2021:13, 21 pp. Let $A$ and $B$ be subsets of an Abelian group. Their sumset $A+B$ is defined to be the set of all $a+b$ such that $a\in A$ and $b\in B$.
Brandon Hanson, Giorgis Petridis
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Supersaturation and stability for forbidden subposet problems [PDF]
We address a supersaturation problem in the context of forbidden subposets. A family $\mathcal{F}$ of sets is said to contain the poset $P$ if there is an injection $i:P \rightarrow \mathcal{F}$ such that $p \le_P q$ implies $i(p) \subset i (q)$.
Patkos, Balazs
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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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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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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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Random multilinear maps and the Erdős box problem
Random multilinear maps and the Erdős box problem, Discrete Analysis 2021:17, 8 pp. A major theme in extremal combinatorics is determining the maximum number of edges that a graph or hypergraph can have if it does not contain a certain fixed graph or ...
David Conlon +2 more
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Extremal words in morphic subshifts [PDF]
Given an infinite word X over an alphabet A a letter b occurring in X, and a total order \sigma on A, we call the smallest word with respect to \sigma starting with b in the shift orbit closure of X an extremal word of X.
Currie, James D. +3 more
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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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