Results 91 to 100 of about 538 (183)

Linear trees in uniform hypergraphs

European Journal of Combinatorics, 2014
Given a tree T on v vertices and an integer k exceeding one. One can define the k-expansion T^k as a k-uniform linear hypergraph by enlarging each edge with a new, distinct set of (k-2) vertices. Then T^k has v+ (v-1)(k-2) vertices. The aim of this paper is to show that using the delta-system method one can easily determine asymptotically the size of ...
openaire   +3 more sources

Wickets in 3-uniform hypergraphs

Discrete Mathematics
In these notes, we consider a Turán-type problem in hypergraphs. What is the maximum number of edges if we forbid a subgraph? Let $H_n^{(3)}$ be a 3-uniform linear hypergraph, i.e. any two edges have at most one vertex common. A special hypergraph, called {\em wicket}, is formed by three rows and two columns of a $3 \times 3$ point matrix.
openaire   +3 more sources

On the number of $\mathcal {H}$ -free hypergraphs

Forum of Mathematics, Sigma
Two central problems in extremal combinatorics are concerned with estimating the number $\mathrm {ex}(n,\mathcal {H})$ , the size of the largest $\mathcal {H}$ -free hypergraph on n vertices, and the number $\mathrm {forb}(n,\mathcal {H})$
Tao Jiang, Sean Longbrake
doaj   +1 more source

Asymptotic Sharpness of Bounds on Hypertrees

Discussiones Mathematicae Graph Theory, 2017
The hypertree can be defined in many different ways. Katona and Szabó introduced a new, natural definition of hypertrees in uniform hypergraphs and investigated bounds on the number of edges of the hypertrees.
Lin Yi, Kang Liying, Shan Erfang
doaj   +1 more source

A note on self-complementary 4-uniform hypergraphs [PDF]

Opuscula Mathematica, 2005
We prove that a permutation \(\theta\) is complementing permutation for a \(4\)-uniform hypergraph if and only if one of the following cases is satisfied: (i) the length of every cycle of \(\theta\) is a multiple of \(8\), (ii) \(\theta\) has \(1\), \(2\)
Artur Szymański
doaj  

Correcting a Graph Into a Linegraph Minimizing Hamming Distance Edition Is NP-Complete and FPT by Treewidth

Journal of Graph Algorithms and Applications
Since Beineke's work in 1968 on linegraphs, attention has focused on the classification of graphs as linegraphs. It is known that every graph $G$ is the linegraph of an hypergraph, and the question is to characterize that root graph.
Dominique Barth, Dimitri Watel, Marc-Antoine Weisser   +2 more
doaj   +1 more source

Enumeration of unlabeled uniform hypergraphs

Discrete Mathematics, 2014
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
openaire   +2 more sources

Quantum walks on regular uniform hypergraphs. [PDF]

Sci Rep, 2018
Liu Y, Yuan J, Duan B, Li D.
europepmc   +1 more source

Online matching on 3-uniform hypergraphs

Mathematical Programming
Abstract The online matching problem was introduced by Karp, Vazirani and Vazirani (STOC 1990) on bipartite graphs with vertex arrivals. It is well-known that the optimal competitive ratio is $$1-1/e$$
S.J. Borst (Sander), D. Kashaev (Danish), Z.K. Koh (Zhuan Khye)   +2 more
openaire   +7 more sources

Coloring [Formula: see text]-Embeddable [Formula: see text]-Uniform Hypergraphs. [PDF]

Discrete Comput Geom, 2014
Heise CG, Panagiotou K, Pikhurko O, Taraz A.   +3 more
europepmc   +1 more source