Investigating the b-chromatic number of bipartite graphs by using the bicomplement

  • Authors:
  • Mais Alkhateeb;Anja Kohl

  • Affiliations:
  • -;-

  • Venue:
  • Discrete Applied Mathematics
  • Year:
  • 2014

Quantified Score

Hi-index 0.04

Visualization

Abstract

A b-coloring of a graph G by k colors is a proper vertex coloring such that every color class contains a color-dominating vertex, that is, a vertex having neighbors in all other k-1 color classes. The b-chromatic number @g"b(G) is the maximum integer k for which G has a b-coloring by k colors. For a bipartite graph G=(A@?B,E), the bicomplement of G is the bipartite graph G@?=(A@?B,E@?) with E@?:={{a,b}|a@?A,b@?B,{a,b}@?E}. In this paper, we investigate the b-chromatic number for bipartite graphs with a special bicomplement. In particular, we consider graphs G for which G@? is disconnected or has maximum degree @D(G@?)@?2. Moreover, we give partial answers to the question ''Which d-regular bipartite graphs G satisfy @g"b(G)=d+1?'' and we show a Nordhaus-Gaddum-type result for G and G@?.