A 3-uniform hypergraph is called a minimum 3-tree, if for any 3coloring of its vertex set there is a heterochromatic edge and the hypergraph has the minimum possible number of edges. Here we show that the number of edges in such 3-tree is for any number of vertices n ≡ 3, 4 (mod 6).
The size of minimum 3-trees
✍ Scribed by Jorge L. Arocha; Joaquín Tey
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 199 KB
- Volume
- 54
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
A 3‐uniform hypergraph (3‐graph) is said to be tight, if for any 3‐partition of its vertex set there is a transversal triple. We give the final steps in the proof of the conjecture that the minimum number of triples in a tight 3‐graph on n vertices is exactly $\left\lceil n(n-2)/3 \right\rceil$. © 2006 Wiley Periodicals, Inc. J Graph Theory 54: 103–114, 2007
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