Ends in spanning trees
โ Scribed by Xingxing Yu
- Publisher
- Elsevier Science
- Year
- 1992
- Tongue
- English
- Weight
- 97 KB
- Volume
- 104
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
โฆ Synopsis
We refer to for terminology not specified here. Graphs mentioned in this note are undirected, simple. The following definition is due to Halin [l]: an end E of an infinite graph G is a set of l-way infinite paths in G such that P, Q E E iff for any finite subset R of V(G) there is a finite path in G -R joining P and Q.
An end E of G is free if there is an finite subset R of the vertex set V(G) such that G -R has a component whose l-way infinite paths belong to E. Zelinka [3] proved that any spanning tree of a connected infinite locally finite graph G contains at least one l-way infinite path from any free end of G, and he conjectured that the word 'free' can be dropped.
In this note, we prove the following stronger result.
๐ SIMILAR VOLUMES
We prove that any connected graph that contains no subdivision of an โต 1regular tree has an end-faithful spanning tree; and furthermore that it has a rayless spanning tree if all its ends are dominated. This improves a result of Seymour and Thomas (An end-faithful spanning tree counterexample, Discr