Aarhus Universitets segl

Stratified hyperkähler spaces

Maxence Mayrand (University of Oxford)
Onsdag 6. februar 2019 13:00–14:00 Aud. D1 (1531-113)
Symplectic reduction is the natural quotient construction in symplectic geometry. Given a free and Hamiltonian action of a compact Lie group G on a symplectic manifold M, this produces a new symplectic manifold of dimension dim(M) - 2 dim(G). If we drop the freeness assumption, the reduced space is usually fairly singular, but Sjamaar-Lerman showed that we can still decompose it into smooth symplectic manifolds which “fit together nicely” in a precise sense. In this talk, I will explain how to get an analogue of Sjamaar-Lerman’s result in hyperkähler geometry and give interesting examples coming from the so-called Nahm equations.
Organiseret af: QGM
Kontakt: William E. Petersen Revideret: 25.05.2023