Suchergebnisse

We give a new, purely algebraic proof of the vanishing of the third de Rham cohomology group of an orbit of a compact Lie group. This proof is based on two lemmas on root systems and on a cubic identity satisfied by the structure constants of a simple complex Lie algebra.

The purpose of this paper is to prove that all graphs G,(m,n) defined by Doyen and Van Diest are hypohamiltonian for every odd integer t > 3.

We realise the *-representation program for compact semi simple Lie groups, using a Kodaira's map and Berezin's symbols. We study the Fourier transform it induces. We show that injectivity of Kodaira's map selects the data of geometric quantization. In this case an inverse of Kodaira's map is given by a moment map. This relates our construction to existing ones.

In this article we give a solution of Yang-Mills equations for the group G = SU(2) on the pseudo-riemannian manifold S1xS3 which is a conformai compactification of Minkowski space.

We suggest a construction of a Moyal type * product on Hermitian symmetric spaces ; this construction is motivated by what happens for coadjoint orbits of the Heisenberg group.