<b>Planar Signed Graphs Whose Circular Chromatic Number Is Between 14 3 and 6</b>
In 2020, Naserasr, Wang and Zhu in 6 constructed a signed planar graph G,s that has a c G = 4 . Moreover every planar signed graph G,s has a c G 6. This paper continues to reinforce this result by using a method allowing to construct, for each rational r 6, a signed planar graph G,s whose c G = r. Considering the previous findings of Moser 2 in 1997 and Zhu 17 in 2001, this clearly indicates that any rational r is the circular chromatic number of a planar signed graph.
Planar signed graphs, circular coloring, circular r coloring
25-31
Issue-1
Volume-7
P. D Ebode Atangana