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On the Decay of Crossing Numbers

Fox, Jacob and Tóth, Csaba D. (2007) On the Decay of Crossing Numbers. [Conference Paper]

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Abstract

The crossing number $\cn(G)$ of a graph $G$ is the minimum number of crossings over all drawings of $G$ in the plane. In 1993, Richter and Thomassen [13] conjectured that there is a constant $c$ such that every graph $G$ with crossing number $k$ has an edge $e$ such that $\cn(G-e) \geq k-c\sqrt{k}$. They showed only that $G$ always has an edge $e$ with $\cn(G-e) \geq \frac{2}{5}\cn(G)-O(1)$. We prove that for every fixed $\epsilon>0$, there is a constant $n_0$ depending on $\epsilon$ such that if $G$ is a graph with $n>n_0$ vertices and $m>n^{1+\epsilon}$ edges, then $G$ has a subgraph $G'$ with at most $(1-\frac{1}{24\epsilon})m$ edges such that $\cn(G') \geq (\frac{1}{28}-o(1))\cn(G)$.

Item Type:Conference Paper
Classifications:G Algorithms and Complexity > G.420 Crossings
Z Theory > Z.999 Others
ID Code:772
Deposited By:GDEA, Administration
Deposited On:04 May 2007
Last Modified:18 May 2009 13:07
Alternative Locations:http://www.springer.com/dal/home/computer/lncs?SGWID=1-164-22-173721109-0

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