Results 11 to 20 of about 87 (83)
A Finite Characterization and Recognition of Intersection Graphs of Hypergraphs with Rank at Most 3 and Multiplicity at Most 2 in the Class of Threshold Graphs [PDF]
Discussiones Mathematicae Graph Theory, 2017 We characterize the class L32$L_3^2 $ of intersection graphs of hypergraphs with rank at most 3 and multiplicity at most 2 by means of a finite list of forbidden induced subgraphs in the class of threshold graphs.
Metelsky Yury +2 more
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Large hypergraphs without tight cycles [PDF]
, 2021 An \(r\)-uniform tight cycle of length \(\ell>r\) is a hypergraph with vertices \(v_1,\dots,v_\ell\) and edges \(\{v_i,v_{i+1},\dots,v_{i+r-1}\}\) (for all \(i\)), with the indices taken modulo \(\ell\). It was shown by Sudakov and Tomon that for each
Janzer, Barnabás, Barnabás Janzer
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Disjoint dijoins for classes of dicuts in finite and infinite digraphs [PDF]
, 2022 A dicut in a directed graph is a cut for which all of its edges are directed to a common side of the cut. A famous theorem of Lucchesi and Younger states that in every finite digraph the least size of a set of edges meeting every non-empty dicut equals ...
Heuer, Karl +3 more
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Cyclic Partitions of Complete and Almost Complete Uniform Hypergraphs
Discussiones Mathematicae Graph Theory, 2022 We consider cyclic partitions of the complete k-uniform hypergraph on a finite set V, minus a set of s edges, s ≥ 0. An s-almost t-complementary k-hypergraph is a k-uniform hypergraph with vertex set V and edge set E for which there exists a permutation ...
Dilbarjot, Gosselin Shonda Dueck
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The Lagrangian Density of {123, 234, 456} and the Turán Number of its Extension
Discussiones Mathematicae Graph Theory, 2021 Given a positive integer n and an r-uniform hypergraph F, the Turán number ex(n, F ) is the maximum number of edges in an F -free r-uniform hypergraph on n vertices.
Chen Pingge, Liang Jinhua, Peng Yuejian
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Asymptotic Enumeration of Non-Uniform Linear Hypergraphs
Discussiones Mathematicae Graph Theory, 2022 A linear hypergraph, also known as a partial Steiner system, is a collection of subsets of a set such that no two of the subsets have more than one element in common.
Hasheminezhad Mahdieh, McKay Brendan D.
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Niche Hypergraphs of Products of Digraphs
Discussiones Mathematicae Graph Theory, 2020 If D = (V, A) is a digraph, its niche hypergraph Nℋ(D) = (V, ℰ) has the edge set ℰ={e⊆V||e|≥2∧∃ υ∈V:e=ND−(υ)∨e=ND+(υ)}{\cal E} = \{ {e \subseteq V| | e | \ge 2 \wedge \exists \, \upsilon \in V:e = N_D^ - ( \upsilon ) \vee e = N_D^ + ( \upsilon ...
Sonntag Martin, Teichert Hanns-Martin
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High Girth Hypergraphs with Unavoidable Monochromatic or Rainbow Edges
Discussiones Mathematicae Graph Theory, 2022 A classical result of Erdős and Hajnal claims that for any integers k, r, g ≥ 2 there is an r-uniform hypergraph of girth at least g with chromatic number at least k.
Axenovich Maria, Karrer Annette
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Rainbow spanning structures in graph and hypergraph systems
Forum of Mathematics, Sigma, 2023 We study the following rainbow version of subgraph containment problems in a family of (hyper)graphs, which generalizes the classical subgraph containment problems in a single host graph. For a collection $\mathit {\mathbf {G}}=\{G_1, G_2,\ldots , G_{
Yangyang Cheng +3 more
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The complexity of recognizing $ABAB$-free hypergraphs [PDF]
Discrete Mathematics & Theoretical Computer ScienceThe study of geometric hypergraphs gave rise to the notion of $ABAB$-free hypergraphs. A hypergraph $\mathcal{H}$ is called $ABAB$-free if there is an ordering of its vertices such that there are no hyperedges $A,B$ and vertices $v_1,v_2,v_3,v_4$ in this
Gábor Damásdi +3 more
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