An injective version of the 1-2-3 Conjecture
Résumé
In this work, we introduce and study a new graph labelling problem standing as a combination of the 1-2-3 Conjecture and injective colouring of graphs, which also finds connections with the notion of graph irregularity. In this problem, the goal, given a graph G, is to label the edges of G so that every two vertices having a common neighbour get incident to different sums of labels. We are interested in the minimum k such that G admits such a k-labelling. We suspect that almost all graphs G can be labelled this way using labels 1,...,∆(G). Towards this speculation, we provide bounds on the maximum label value needed in general. In particular, we prove that using labels 1,...,∆(G) is indeed sufficient when G is a tree, a particular cactus, or when its injective chromatic number χi(G) is equal to ∆(G).
Domaines
Mathématique discrète [cs.DM]Origine | Fichiers produits par l'(les) auteur(s) |
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