学术报告（刘润球 2025.1.6）

摘要：In this talk, I will first describe the reasons why the Kerr metric is so important in the research in GR and relativistic astrophysics in the modern era, citing the outstanding problems in gravitational wave detection as well as the MHD related to jet phenomenon in supermassive black holes as examples. Then I will present the
understanding of the geometry of rotation of a Kerr black hole by a 2d quasi conformal map. Using this geometric picture and spinors, a Penrose type geometric inequality is proven for axisymmetric black holes with angular momentum. The quasi conformal map construction affords a further generalisation to the initial data of binary rotating black holes. Numerical waveforms for the head on and inspiral of two rotating black holes will then be presented.