GD 1995: Graph Drawing pp 463-471

# Crossing numbers of meshes

• Ondrej Sýkora
• László A. Székely
• Imrich Vrt'o
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1027)

## Abstract

We prove that the crossing number of the cartesian product of 2 cycles, Cm× Cn, m≤n, is of order Ω(mn), improving the best known lower bound. In particular we show that the crossing number of Cm×Cn is at least mn/90, and for n=m, m+1 we reduce the constant 90 to 6. This partially answers a 20-years old question of Harary, Kainen and Schwenk [3] who gave the lower bound m and the upper bound (m−2)n and conjectured that the upper bound is the actual value of the crossing number for Cm×Cn. Moreover, we extend this result to k≥3 cycles and paths, and obtain such lower and upper bounds on the crossing numbers of the corresponding meshes, which differ by a small constant only.

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