To cheer you up in difficult times 34: Ringel Circle Problem solved by James Davies, Chaya Keller, Linda Kleist, Shakhar Smorodinsky, and Bartosz Walczak
Combinatorics and more 2021-12-11
Summary:
Gerhard Ringel considered in 1959 the following: Consider a finite family of circles such that every point in the plane is included in at most two circles. What is the minimum number of colors needed to color the circles so … Continue reading →