2021/04/23 by Jing, Wang, Zuozheng, Zhang
#Combinatorics (math.CO) #FOS: Mathematics
paper · doi:10.48550/arxiv.2104.11640
The crossing number of a graph G in a surface Σ, denoted by crΣ(G), is the minimum number of pairwise intersections of edges in a drawing of G in Σ. Let k be an integer satisfying k≥ 3, the generalized Petersen graph P(3k,k) is the graph with vertex set V(P(3k,k))=\ui, vi| i=1,2,⋯,3k\ and edge set E(P(3k,k))=\uiui+1, uivi, vivk+i| i=1,2,⋯,3k\, the subscripts are read modulo 3k. This paper investigates the crossing number of P(3k,k) in the projective plane. We determine the exact value of crN1(P(3k,k)) is k-2 when 3≤ k≤ 7, moreover, for k≥ 8, we get that k-2≤ crN1(P(3k,k))≤ k-1.