"Orbitopes"

Raman Sanyal
UC Berkeley

Monday, November 2, 2009
4:00 pm, 845 Patterson Office Tower

Abstract:

An orbitope is the convex hull of an orbit in a real representation of a compact group. For finite groups orbitopes yield very nice polytopes, among them the regular solids, Coxeter permutahedra, and even-dimensional cyclic polytopes. In general, orbitopes are not polyhedral and thus much harder to work with. In this talk I will discuss basic properties and questions related to orbitopes but, mainly, I will show many examples most of which behave like continuous versions of known polytopes. This is joint work with Frank Sottile and Bernd Sturmfels.