M.Sc. Paul Zellhofer
Doctoral student
Christian-Albrechts-Universität zu Kiel
E-mail: zellhofer(at)math.uni-kiel.de
Project
61At infinity of symmetric spaces
Publications within SPP2026
We prove an analogue of Kostant's convexity theorem for split real and complex Kac-Moody groups associated to free and cofree root data. The result can be seen as a first step towards describing the multiplication map in a Kac-Moody group in terms of Iwasawa coordinates. Our method involves a detailed analysis of the geometry of Weyl group orbits in the Cartan subalgebra of a real Kac-Moody algebra. It provides an alternative proof of Kostant convexity for semisimple Lie groups and also generalizes a linear analogue of Kostant's theorem for Kac-Moody algebras that has been established by Kac and Peterson in 1984.
Related project(s):
61At infinity of symmetric spaces