Journal article
Cycles through all finite vertex sets in infinite graphs
A closed curve in the Freudenthal compactification |G| of an infinite locally finite graph G is called a Hamiltonian curve if it meets every vertex of G exactly once (and hence it meets every end at least once). We prove that |G| has a Hamiltonian curve if and only if every finite vertex set of G is contained in a cycle of G.
We apply this to extend a number of results and conjectures on finite graphs to Hamiltonian curves in infinite locally finite graphs. For example, Barnette’s conjecture (that every finite planar cubic 3-connected bipartite graph is Hamiltonian) is equivalent to the statement that every one-ended planar cubic 3-connected bipartite graph has a Hamiltonian curve.
It is also equivalent to the statement that every planar cubic 3-connected bipartite graph with a nowhere-zero 3-flow (with no restriction on the number of ends) has a Hamiltonian curve. However, there are 7-ended planar cubic 3-connected bipartite graphs that do not have a Hamiltonian curve.
Language: | English |
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Publisher: | Elsevier BV |
Year: | 2017 |
Pages: | 259-275 |
ISSN: | 10959971 and 01956698 |
Types: | Journal article |
DOI: | 10.1016/j.ejc.2017.06.006 |
ORCIDs: | Thomassen, Carsten |