Facial colorings using Hall's Theorem
Résumé
A vertex coloring of a plane graph is ℓ-facial if every two distinct vertices joined by a facial walk of length at most ℓ receive distinct colors. It has been conjectured that every plane graph has an ℓ-facial coloring with at most 3ℓ+1 colors. We improve the currently best known bound and show that every plane graph has an ℓ-facial coloring with at most 7ℓ/2+6 colors. Our proof uses the standard discharging technique, however, in the reduction part we have successfully applied Hall's Theorem, which seems to be quite an unusual approach in this area.
Domaines
Mathématique discrète [cs.DM]
Origine : Fichiers produits par l'(les) auteur(s)
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