Spectral Graph Theory Lecture 25 Planar Graphs , part 1 Daniel
نویسنده
چکیده
Planar graphs originated with the studies of polytopes and of maps. The skeleton (edges) of a threedimensional polytope provide a planar graph. We obtain a planar graph from a map by representing countries by vertices, and placing edges between countries that touch each other. Assuming each country is contiguous, this gives a planar graph. While planar graphs were introduced for practical reasons, they posess many remarkable mathematical properties. This is one reason we will study them.
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