scholarly journals Minimum vertex degree condition for tight Hamiltonian cycles in 3‐uniform hypergraphs

2019 ◽  
Vol 119 (2) ◽  
pp. 409-439 ◽  
Author(s):  
Christian Reiher ◽  
Vojtěch Rödl ◽  
Andrzej Ruciński ◽  
Mathias Schacht ◽  
Endre Szemerédi
Keyword(s):  
Vertex Degree ◽  
Hamiltonian Cycles ◽  
Degree Condition ◽  
Uniform Hypergraphs

scholarly journals Minimum pair degree condition for tight Hamiltonian cycles in 4-uniform hypergraphs

2020 ◽  
Vol 161 (2) ◽  
pp. 647-699
Author(s):  
J. Polcyn ◽  
Chr. Reiher ◽  
V. Rödl ◽  
A. Ruciński ◽  
M. Schacht ◽  
...  
Keyword(s):  
Hamiltonian Cycles ◽  
Degree Condition ◽  
Uniform Hypergraphs

Decomposing Complete 3-Uniform Hypergraph into 5-Cycles

2014 ◽  
Vol 672-674 ◽  
pp. 1935-1939
Author(s):  
Guan Ru Li ◽  
Yi Ming Lei ◽  
Jirimutu
Keyword(s):  
Positive Integer ◽  
Hamiltonian Cycles ◽  
Uniform Hypergraph ◽  
Design Algorithm ◽  
Uniform Hypergraphs ◽  
Edge Partition ◽  
Definition Of

About the Katona-Kierstead definition of a Hamiltonian cycles in a uniform hypergraph, a decomposition of complete k-uniform hypergraph Kn(k) into Hamiltonian cycles studied by Bailey-Stevens and Meszka-Rosa. For n≡2,4,5 (mod 6), we design algorithm for decomposing the complete 3-uniform hypergraphs into Hamiltonian cycles by using the method of edge-partition. A decomposition of Kn(3) into 5-cycles has been presented for all admissible n≤17, and for all n=4m +1, m is a positive integer. In general, the existence of a decomposition into 5-cycles remains open. In this paper, we use the method of edge-partition and cycle sequence proposed by Jirimutu and Wang. We find a decomposition of K20(3) into 5-cycles.

scholarly journals Triangle-degrees in graphs and tetrahedron coverings in 3-graphs

2020 ◽  
pp. 1-25
Author(s):  
Victor Falgas-Ravry ◽  
Klas Markström ◽  
Yi Zhao
Keyword(s):  
Upper Bound ◽  
Vertex Degree ◽  
Covering Problem ◽  
Uniform Hypergraphs ◽  
Vertex Graph ◽  
Optimal Bounds ◽  
Special Instance ◽  
Tripartite Graphs

Abstract We investigate a covering problem in 3-uniform hypergraphs (3-graphs): Given a 3-graph F, what is c1(n, F), the least integer d such that if G is an n-vertex 3-graph with minimum vertex-degree $\delta_1(G)>d$ then every vertex of G is contained in a copy of F in G? We asymptotically determine c1(n, F) when F is the generalized triangle $K_4^{(3)-}$ , and we give close to optimal bounds in the case where F is the tetrahedron $K_4^{(3)}$ (the complete 3-graph on 4 vertices). This latter problem turns out to be a special instance of the following problem for graphs: Given an n-vertex graph G with $m> n^2/4$ edges, what is the largest t such that some vertex in G must be contained in t triangles? We give upper bound constructions for this problem that we conjecture are asymptotically tight. We prove our conjecture for tripartite graphs, and use flag algebra computations to give some evidence of its truth in the general case.

scholarly journals A note on the edge reconstruction conjecture

1975 ◽  
Vol 12 (1) ◽  
pp. 27-30 ◽  
Author(s):  
E.F. Schmeichel
Keyword(s):  
Degree Sequence ◽  
Existence Condition ◽  
Vertex Degree ◽  
Hamiltonian Cycles ◽  
Edge Reconstruction

Let G be a graph with vertex degree sequence d1 ≤ d2 ≤ … ≤ dp It is shown that if di + dp–i+1 ≥ p for some i, then G is uniquely reconstructable from its collection of maximal (edge deleted) subgraphs. This generalizes considerably a result of Lovász. As a corollary, it is shown that Chvátal's existence condition for hamiltonian cycles implies edge reconstructability as well.

scholarly journals Vertex Degree Sums for Matchings in 3-Uniform Hypergraphs

10.37236/8627 ◽  
2019 ◽  
Vol 26 (4) ◽  
Author(s):  
Yi Zhang ◽  
Yi Zhao ◽  
Mei Lu
Keyword(s):  
Vertex Degree ◽  
Uniform Hypergraph ◽  
Degree Sum ◽  
Uniform Hypergraphs ◽  
Positive Integers ◽  
Degree Sum Condition

Let $n, s$ be positive integers such that $n$ is sufficiently large and $s\le n/3$. Suppose $H$ is a 3-uniform hypergraph of order $n$ without isolated vertices. If $\deg(u)+\deg(v) > 2(s-1)(n-1)$ for any two vertices $u$ and $v$ that are contained in some edge of $H$, then $H$ contains a matching of size $s$. This degree sum condition is best possible and confirms a conjecture of the authors [Electron. J. Combin. 25 (3), 2018], who proved the case when $s= n/3$.

scholarly journals Decomposing complete 3-uniform hypergraph K_{n}^{(3)} into 7-cycles

2019 ◽  
Vol 39 (3) ◽  
pp. 383-393
Author(s):  
Meihua Meihua ◽  
Meiling Guan ◽  
Jirimutu Jirimutu
Keyword(s):  
Positive Integer ◽  
Hamiltonian Cycle ◽  
Hamiltonian Cycles ◽  
Uniform Hypergraph ◽  
Uniform Hypergraphs ◽  
Edge Partition ◽  
Definition Of

We use the Katona-Kierstead definition of a Hamiltonian cycle in a uniform hypergraph. A decomposition of complete \(k\)-uniform hypergraph \(K^{(k)}_{n}\) into Hamiltonian cycles was studied by Bailey-Stevens and Meszka-Rosa. For \(n\equiv 2,4,5\pmod 6\), we design an algorithm for decomposing the complete 3-uniform hypergraphs into Hamiltonian cycles by using the method of edge-partition. A decomposition of \(K^{(3)}_{n}\) into 5-cycles has been presented for all admissible \(n\leq17\), and for all \(n=4^{m}+1\) when \(m\) is a positive integer. In general, the existence of a decomposition into 5-cycles remains open. In this paper, we show if \(42~|~(n-1)(n-2)\) and if there exist \(\lambda=\frac{(n-1)(n-2)}{42}\) sequences \((k_{i_{0}},k_{i_{1}},\ldots,k_{i_{6}})\) on \(D_{all}(n)\), then \(K^{(3)}_{n}\) can be decomposed into 7-cycles. We use the method of edge-partition and cycle sequence. We find a decomposition of \(K^{(3)}_{37}\) and \(K^{(3)}_{43}\) into 7-cycles.

On Perfect Matchings in Uniform Hypergraphs with Large Minimum Vertex Degree

2009 ◽  
Vol 23 (2) ◽  
pp. 732-748 ◽  
Author(s):  
Hip Hàn ◽  
Yury Person ◽  
Mathias Schacht
Keyword(s):  
Perfect Matchings ◽  
Vertex Degree ◽  
Uniform Hypergraphs

Hamiltonian decompositions of prisms over complete 3-uniform hypergraphs

2015 ◽  
Vol 07 (03) ◽  
pp. 1550031
Author(s):  
Ratinan Boonklurb ◽  
Sirirat Singhun ◽  
Sansanee Termtanasombat
Keyword(s):  
Hamiltonian Cycles ◽  
Uniform Hypergraphs ◽  
Hamiltonian Decompositions

We consider prisms over complete 3-uniform hypergraphs and decompose them into Hamiltonian cycles of Katona–Kierstead type. We show that prisms over complete 3-uniform hypergraphs of order 4, 5 and 8 can be decomposed into Hamiltonian cycles and we suggest that prisms over complete 3-uniform hypergraphs of order in the form 6t + 2 may have Hamiltonian decompositions.

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