Crossing numbers of graph embedding pairs on closed surfaces
Seiya Negami · Journal of Graph Theory · 2001
We shall prove that any two graphs G1 and G2 can be embedded together on a closed surface of genus g with at most 4g · β(G1) · β(G2) crossing points on their edges if they are embeddable on the surface, where β(G) stands for the Betti number of G, and show several observations on crossings of graph embedding pairs. © 2000 John Wiley & Sons, Inc. J Graph Theory 36: 8–23, 2001