Emmy-Noether-Seminar

Biquotients in symplectic geometry

Oliver Goertsches (Marburg)

Abstract: Biquotients are generalizations of homogeneous spaces that naturally occur in Riemannian geometry, mostly in regard to questions concerning positive and nonnegative curvature. In this talk we will explain why they are also of interest in symplectic and Kähler geometry, by constructing many such structures on equal rank biquotients. Particular emphasis will be put on Eschenburg’s twisted flag manifold SU(3)//T, which we will compare to Tolman’s and Woodward’s examples of symplectic manifolds admitting Hamiltonian non-Kähler torus actions. (This is joint work with Panagiotis Konstantis and Leopold Zoller.)