Results 51 to 60 of about 13,803 (191)
Simple juntas for shifted families
Discrete Analysis, 2020 **For the moment the link is to the submitted version of the article. It will be updated when the final version has been posted to arXiv.** Simple juntas for shifted families, Discrete Analysis 2020:14, 18 pp.
Peter Frankl, Andrey Kupavskii
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On the Turan number of forests [PDF]
, 2012 The Turan number of a graph H, ex(n,H), is the maximum number of edges in a graph on n vertices which does not have H as a subgraph. We determine the Turan number and find the unique extremal graph for forests consisting of paths when n is sufficiently ...
Lidický, Bernard +2 more
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Further results on permanents of Laplacian matrices of trees
Open MathematicsThe research on the permanents of graph matrices is one of the contemporary research topic in algebraic combinatorics. Brualdi and Goldwasser characterized the upper and lower bounds of permanents of Laplacian matrices of trees.
Wu Tingzeng, Dong Xiangshuai
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Extremal, enumerative and probabilistic results on ordered hypergraph matchings
Forum of Mathematics, SigmaAn ordered r-matching is an r-uniform hypergraph matching equipped with an ordering on its vertices. These objects can be viewed as natural generalisations of r-dimensional orders.
Michael Anastos +3 more
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Hypergraph removal lemmas via robust sharp threshold theorems
Discrete Analysis, 2020 Hypergraph removal lemmas via robust sharp threshold theorems, Discrete Analysis 2020:10, 46 pp. A central result in additive and extremal combinatorics is the triangle removal lemma, which roughly speaking states that a graph with few triangles can be ...
Noam Lifshitz
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Improving bounds on packing densities of 4-point permutations
, 2018 We consolidate what is currently known about packing densities of 4-point permutations and in the process improve the lower bounds for the packing densities of 1324 and 1342.
Sliacan, Jakub, Stromquist, Walter
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Cacti with Extremal PI Index [PDF]
, 2016 The vertex PI index $PI(G) = \sum_{xy \in E(G)} [n_{xy}(x) + n_{xy}(y)]$ is a distance-based molecular structure descriptor, where $n_{xy}(x)$ denotes the number of vertices which are closer to the vertex $x$ than to the vertex $y$ and which has been the
Wang, Chunxiang +2 more
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Beyond sum-free sets in the natural numbers [PDF]
, 2014 For an interval [1,N]⊆N, sets S⊆[1,N] with the property that |{(x,y)∈S2:x+y∈S}|=0, known as sum-free sets, have attracted considerable attention. In this paper, we generalize this notion by considering r(S)=|{(x,y)∈S2:x+y∈S}|, and analyze its behaviour ...
Huczynska, Sophie
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Kneser graphs are like Swiss cheese
Discrete Analysis, 2018 Kneser graphs are like Swiss cheese, Discrete Analysis 2018:2, 18 pp. This paper relates two very interesting areas of research in extremal combinatorics: removal lemmas, and influence of variables.
Ehud Friedgut, Oded Regev
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Integer colorings with forbidden rainbow sums
, 2020 For a set of positive integers $A \subseteq [n]$, an $r$-coloring of $A$ is rainbow sum-free if it contains no rainbow Schur triple. In this paper we initiate the study of the rainbow Erd\H{o}s-Rothchild problem in the context of sum-free sets, which ...
Cheng, Yangyang +4 more
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