Universität Augsburg

Dr. Leopold Zoller
LMU
spricht am
Montag, 15. Juni 2020
um
16:00 Uhr
im
Zoom
über das Thema:
Abstract: 
In the mid 90s, Tolman gave a remarkable example of a Hamiltonian torus action in dimension 6 which does not admit a compatible Kähler structure. We will analyse this example from the point of view of GKM theory, which associates to certain manifolds a labelled graph. In dimension 6, it turns out that the graph determines the manifold up to diffeomorphism, which lets us identify Tolman’s example as Eschenburg’s twisted flag. Conversely, we give a construction which realizes graph fibrations in dimension 6 through fiber bundles. As a consequence, we see that Tolman’s example is part of a large family of manifolds whose graphs enjoy similar properties. By relating properties of the graphs to geometric structures, we find many more examples of Hamiltonian nonKähler actions. This is joint work with Oliver Goertsches and Panagiotis Konstantis. 
Hierzu ergeht herzliche Einladung. 
Prof. Dr. Bernhard Hanke 