Any r-edge-coloured n-vertex complete graph K n contains at most r monochromatic trees, all of different colours, whose vertex sets partition the vertex set of K n , provided n 3r 4 r! (1&1Âr) 3(1&r) log r. This comes close to proving, for large n, a conjecture of Erdo s, Gya rfa s, and Pyber, which
Partitioning complete multipartite graphs by monochromatic trees
✍ Scribed by Atsushi Kaneko; M. Kano; Kazuhiro Suzuki
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 102 KB
- Volume
- 48
- Category
- Article
- ISSN
- 0364-9024
No coin nor oath required. For personal study only.
✦ Synopsis
The tree partition number of an r-edge-colored graph G, denoted by t r (G), is the minimum number k such that whenever the edges of G are colored with r colors, the vertices of G can be covered by at most k vertex-disjoint monochromatic trees. We determine t 2 (K (n 1 ; n 2 ; . . . ; n k )) of the complete k-partite graph K (n 1 ; n 2 ; . . . ; n k ). In particular, we prove that t 2 (K (n; m)) ¼ b(m À 2)=2 n c þ 2, where 1 n m.
📜 SIMILAR VOLUMES
For a positive integer k, a set of k + 1 vertices in a graph is a k-cluster if the difference between degrees of any two of its vertices is at most k -1. Given any tree T with at least k 3 edges, we show that for each graph G of sufficiently large order, either G or its complement contains a copy of