Brian Whetter

Hugo Hadwiger proved in 1957 that any continuous rigid-motion-invariantvaluation on the set of compact convex sets inRncan be written as a linearcombination of the intrinsic volumes. Daniel Klain, through some clever“cut and paste” arguments and a trick involving zonoids, was able toshorten the proof. This talk will discuss what valuations and intrinsicvolumes are and then outline Klain’s proof of the theorem.