论文信息 - On the Chromatic Number of R 4

On the Chromatic Number of R 4

The lower bound for the chromatic number of R4 is improved from 7 to 9. Three graphs with unit distance embeddings in R4 are described. The first is a 7-chromatic graph of order 14 whose chromatic number can be verified by inspection. The second is an 8-chromatic graph of order 26. In this case the chromatic number can be verified quickly by a simple computer program. The third graph is a 9-chromatic graph of order 65 for which computer verification takes about one minute.

Geoffrey Exoo | Dan Ismailescu | Michael Lim

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