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arXiv · 1103.2724

Lower bounds on the obstacle number of graphs

Padmini Mukkamala·János Pach·Dömötör Pálvölgyi
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Abstract

Given a graph $G$, an {\em obstacle representation} of $G$ is a set of points in the plane representing the vertices of $G$, together with a set of connected obstacles such that two vertices of $G$ are joined by an edge if and only if the corresponding points can be connected by a segment which avoids all obstacles. The {\em obstacle number} of $G$ is the minimum number of obstacles in an obstacle representation of $G$. It is shown that there are graphs on $n$ vertices with obstacle number at least $Ω({n}/{\log n})$.

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Padmini Mukkamala, János Pach, Dömötör Pálvölgyi. 2011-03-14. Lower bounds on the obstacle number of graphs. https://arxiv.org/abs/1103.2724

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