A Euclidean Ramsey Result in the Plane

Sergei Tsaturian


An old question in Euclidean Ramsey theory asks, if the points in the plane are red-blue coloured, does there always exist a red pair of points at unit distance or five blue points in line separated by unit distances? An elementary proof answers this question in the affirmative.


Euclidean Ramsey theory; Plane; Combinatorial Geometry

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