|
|
|
|
|
Hadwiger's TheoremIn integral geometry (otherwise called geometric probability theory), Hadwiger's theorem states that the space of translation-invariant, finitely additive, not-necessarily-nonnegative set functions defined on finite unions of compact convex sets in Rn consists (up to scalar multiples) of one "measure" that is "homogeneous of degree k" for each k = 0, 1, 2, ..., n, and linear combinations of those "measures". "Homogeneous of degree k" means that rescaling any set by any factor c > 0 multiplies the set's "measure" by ck. The one that is homogeneous of degree n is the ordinary n-dimensional volume. The one that is homogeneous of degree n − 1 is the "surface volume." The one that is homogeneous of degree 1 is a mysterious function called the mean width, a misnomer. The one that is homogeneous of degree 0 is the Euler characteristic. The theorem was proved by Hugo Hadwiger, and led to further work on intrinsic volumes. References An account and a proof of Hadwiger's theorem may be found in Introduction to Geometric Probability by Daniel Klain and Gian-Carlo Rota, Cambridge University Press, 1997.
|
 |
|
| Copyright 2005-2009 OnPedia.com. All Rights Reserved |
|
|