English

Good edge-labelings and graphs with girth at least five

Combinatorics 2012-07-30 v3

Abstract

A good edge-labeling of a graph [Ara\'ujo, Cohen, Giroire, Havet, Discrete Appl. Math., forthcoming] is an assignment of numbers to the edges such that for no pair of vertices, there exist two non-decreasing paths. In this paper, we study edge-labeling on graphs with girth at least 5. In particular we verify, under this additional hypothesis, a conjecture by Ara\'ujo et al. This conjecture states that if the average degree of G is less than 3 and G is minimal without an edge-labeling, then G \in {C_3,K_{2,3}}. (For the case when the girth is 4, we give a counterexample.)

Keywords

Cite

@article{arxiv.1109.1125,
  title  = {Good edge-labelings and graphs with girth at least five},
  author = {Michel Bode and Babak Farzad and Dirk Oliver Theis},
  journal= {arXiv preprint arXiv:1109.1125},
  year   = {2012}
}

Comments

23 pages + appendix