2019/02/27 by Haythorpe, Michael, Newcombe, Alex
#Combinatorics (math.CO) #FOS: Mathematics
paper · doi:10.48550/arxiv.1902.10357
The exact crossing number is only known for a small number of families of graphs. Many of the families for which crossing numbers have been determined correspond to cartesian products of two graphs. Here, the cartesian product of the Sunlet graph, denoted Sn, and the Star graph, denoted K1,m, is considered for the first time. It is proved that the crossing number of Sn \Box K1,2 is n, and the crossing number of Sn \Box K1,3 is 3n. An upper bound for the crossing number of Sn \Box K1,m is also given.