English

Equitable neighbour-sum-distinguishing edge and total colourings

Discrete Mathematics 2017-01-18 v1 Combinatorics

Abstract

With any (not necessarily proper) edge kk-colouring γ:E(G){1,,k}\gamma:E(G)\longrightarrow\{1,\dots,k\} of a graph GG,one can associate a vertex colouring σ_γ\sigma\_{\gamma} given by σ_γ(v)=_evγ(e)\sigma\_{\gamma}(v)=\sum\_{e\ni v}\gamma(e).A neighbour-sum-distinguishing edge kk-colouring is an edge colouring whose associated vertex colouring is proper.The neighbour-sum-distinguishing index of a graph GG is then the smallest kk for which GG admitsa neighbour-sum-distinguishing edge kk-colouring.These notions naturally extends to total colourings of graphs that assign colours to both vertices and edges.We study in this paper equitable neighbour-sum-distinguishing edge colourings andtotal colourings, that is colourings γ\gamma for whichthe number of elements in any two colour classes of γ\gamma differ by at most one.We determine the equitable neighbour-sum-distinguishing indexof complete graphs, complete bipartite graphs and forests,and the equitable neighbour-sum-distinguishing total chromatic numberof complete graphs and bipartite graphs.

Keywords

Cite

@article{arxiv.1701.04648,
  title  = {Equitable neighbour-sum-distinguishing edge and total colourings},
  author = {Olivier Baudon and Monika Pilsniak and Jakub Przybylo and Mohammed Senhaji and Eric Sopena and Mariusz Wozniak},
  journal= {arXiv preprint arXiv:1701.04648},
  year   = {2017}
}