Extreme-mass-ratio binaries (EMRBs) and intermediate-mass-ratio binaries (IMRBs) with a millisecond pulsar are gravitational-wave (GW) sources, which have a guaranteed electromagnetic counterpart, to be observed by LISA. These binaries have complex orbital and spin dynamics caused by spin-orbit and spin-spin coupling (through spin-curvature interaction). The narrow mass range of pulsars (which are neutron stars) greatly reduces the search space in gravitational wave experiments and radio pulsar timing observations. This EMRB-IMEB subgroup will provide us a means to resolve important astrophysical problems, e.g. the validity of extending the M(BH)-sigma scaling for galactic spheroids to the very low-mass galaxies, and whether or not low-mass dwarf galaxies and globular clusters could harbour nuclear intermediate-mass black holes. The extremely high precision that can be achieved in gravitational wave experiments and radio pulsar timing observations will give us the opportunity to directly detect various gravitational clock effects that arisen from different spin couplings. Radio monitoring of the orbital and spin evolution of the millisecond pulsar in EMRBs can be used for deriving practical methods for the correction the phase drifts in the gravitational waves emitted from the EMRBs induced by the high-order mechanisms, such as self-force, a great challenge needed to be resolved before the launch of LISA.

BIO
Prof. Kinwah Wu did his undergraduate at the Chinese University of Hong Kong and PhD at Louisiana State University. He was also a postgraduate student (for 2 years) at University of New South Wales. He worked in NASA-MSFC, Australian National University and University of Sydney before taking up the Head of Theory post at Mullard Space Science Laboratory of University College London (UCL-MSSL) in 2001, which he stepped down two years ago. Apart the Chair (Professor) in Theoretical Astrophysics at UCL, he also held Honorary Professorships at Hong Kong University, University of Sydney and Macquarie University and a Guest Professorship at Nanjing University. He was appointed by the Chinese Academy of Science as 中国科学院 海外评审专家 and served 3 years from 2018 to 2021.

Prof. Kinwah Wu worked mostly on plasma astrophysics and high-energy astrophysics related to compact objects in his early career. The focuses his current research are: covariant radiative transfer in cosmological settings or in extreme gravity, fundamental aspects of general relativity and their manifestation in the gravitational waves and multi-messenger particles from astrophysical systems, and hadronic interactions and ultra-high energy cosmic rays and neutrinos of distant starburst galaxies.