Abstract
A graph G is a k -dot product graph if there exists a vector labelling u:V(G)→R k such that u(i) T u(j)≥1 if and only if ij∈E(G) . Fiduccia, Scheinerman, Trenk and Zito [Discrete Math., 1998] asked whether every planar graph is a 3 -dot product graph. We show that the answer is "no". On the other hand, every planar graph is a 4 -dot product graph. We also answer the corresponding questions for planar graphs of prescribed girth and for outerplanar graphs.
Original language | English |
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Article number | P216 |
Number of pages | 14 |
Journal | Electronic Journal of Combinatorics |
Volume | 18 |
Issue number | 1 |
Publication status | Published - 2011 |
Externally published | Yes |