Crossing Numbers and Cutwidths
Hristo N. Djidjev and Imrich Vrťo
Vol. 7, no. 3, pp. 245-251, 2003. Regular paper.
Abstract The crossing number of a graph G=(V,E), denoted by cr(G), is the smallest number of edge crossings in any drawing of G in the plane. Wee assume that the drawing is good, i.e., incident edges do not cross, two edges cross at most once and at most two edges cross in a point of the plane. Leighton [] proved that for any n-vertex graph G of bounded degree, its crossing number satisfies cr(G)+n=Ω(bw2(G)), where bw(G) is the bisection width of G. The lower bound method was extended for graphs of arbitrary vertex degrees to cr(G)+[1/16] ∑vGdv2 = Ω(bw2(G)) in [,], where dv is the degree of any vertex v. We improve this bound by showing that the bisection width can be replaced by a larger parameter - the cutwidth of the graph. Our result also yields an upper bound for the path-width of G in terms of its crossing number.
Submitted: September 2002.
Revised: June 2003.
Communicated by Giuseppe Liotta
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