Let G be an infinite graph; define de& G to be the least m such that any partition P of the vertex set of G into sets of uniformly bounded cardinality contains a set which is adjacent to at least m Other sets of the partition. If G is either a regular tree 01 a triangtiisr, sqzart or hexagonal plana
Note on vertex-partitions of infinite graphs
✍ Scribed by János Pach; Joel H. Spencer
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 118 KB
- Volume
- 79
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
✦ Synopsis
Given an infinite graph G, let deg,(G) be defined as the smallest d for which V(G) can be partitioned into finite subsets of (uniformly) bounded size such that each part is adjacent to at most d others. A countable graph G is constructed with de&(G) > 2 and with the property that [{y~V(G):d(x, y)sn}lcCn for any xeV(G), n E N. This disproves conjectures of Cenzer and Howorka.
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