Speaker: Nigel Hitchin (FRS, University of Oxford)

Time: 14:00-15:00, Jun 3, 2026

Venue: Lecture Hall, Building 1, Section B, 3rd Floor, USTC Shanghai Institute for Advanced Studies & Tencent Meeting ID: 992 343 965, oasssword: 202606

Calabi introduced the terminology of hyperkähler manifolds and produced the first higher dimensional complete example on the cotangent bundle of complex projective space. The moduli space of Higgs bundles on a Riemann surface has a much-studied hyperkähler metric which has some common features with Calabi's example. The talk will focus on a real-valued function associated to a circle action, applicable in both cases, and show how to use it to describe the geometry of the Higgs bundle moduli space as the complex structure of the Riemann surface varies.