Results 81 to 90 of about 1,405,425 (255)
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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Hypergraphs with infinitely many extremal constructions
Discrete Analysis, 2023 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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On the spectrum of hypergraphs
, 2016 Here we study the spectral properties of an underlying weighted graph of a non-uniform hypergraph by introducing different connectivity matrices, such as adjacency, Laplacian and normalized Laplacian matrices. We show that different structural properties
Chris Ritchie (1952305) +4 more
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Steiner Triple Systems With High Discrepancy
Journal of Combinatorial Designs, Volume 34, Issue 1, Page 5-14, January 2026.ABSTRACT In this paper, we initiate the study of discrepancy questions for combinatorial designs. Specifically, we show that, for every fixed r ≥ 3 and n ≡ 1 , 3 ( mod 6 ), any r‐colouring of the triples on [ n ] admits a Steiner triple system of order n with discrepancy Ω ( n 2 ).
Lior Gishboliner +2 more
wiley +1 more source
A Refined Graph Container Lemma and Applications to the Hard‐Core Model on Bipartite Expanders
Random Structures &Algorithms, Volume 68, Issue 1, January 2026.ABSTRACT We establish a refined version of a graph container lemma due to Galvin and discuss several applications related to the hard‐core model on bipartite expander graphs. Given a graph G$$ G $$ and λ>0$$ \lambda >0 $$, the hard‐core model on G$$ G $$ at activity λ$$ \lambda $$ is the probability distribution μG,λ$$ {\mu}_{G,\lambda } $$ on ...
Matthew Jenssen +2 more
wiley +1 more source
Heliyon, 2022 Topological invariants are numerical parameters of graphs or hypergraphs that indicate its topology and are known as graph or hypergraph invariants. In this paper, topological indices of hypergraphs such as Wiener index, degree distance index and Gutman ...
Sakina Ashraf +3 more
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2-Colorability of r-Uniform Hypergraphs [PDF]
The Electronic Journal of Combinatorics, 2019 A hypergraph is properly 2-colorable if each vertex can be colored by one of two colors and no edge is completely colored by a single color. We present a complete algebraic characterization of the 2-colorability of r-uniform hypergraphs. This generalizes a well known algebraic characterization of k-colorability of graphs due to Alon, Tarsi, Lovasz, de ...
Krul, Michael, Thoma, Luboš
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Counting Independent Sets in Percolated Graphs via the Ising Model
Random Structures &Algorithms, Volume 68, Issue 1, January 2026.ABSTRACT Given a graph G$$ G $$, we form a random subgraph Gp$$ {G}_p $$ by including each edge of G$$ G $$ independently with probability p$$ p $$. We provide an asymptotic expansion of the expected number of independent sets in random subgraphs of regular bipartite graphs satisfying certain vertex‐isoperimetric properties, extending the work of ...
Anna Geisler +3 more
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Recognizing the P_4-structure of claw-free graphs and a larger graph class [PDF]
Discrete Mathematics & Theoretical Computer Science, 2002 The P_4-structure of a graph G is a hypergraph \textbfH on the same vertex set such that four vertices form a hyperedge in \textbfH whenever they induce a P_4 in G.
Luitpold Babel +2 more
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A Cheeger Cut for Uniform Hypergraphs [PDF]
Graphs and Combinatorics, 2021 AbstractThe graph Cheeger constant and Cheeger inequalities are generalized to the case of hypergraphs whose edges have the same cardinality. In particular, it is shown that the second largest eigenvalue of the generalized normalized Laplacian is bounded both above and below by the generalized Cheeger constant, and the corresponding eigenfunctions can ...
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