Recently, Zhengwen Liu from the School of Physics and the Shing-Tung Yau Center at Southeast University, in collaboration with Christoph Dlapa, Gregor Kälin and Rafael A. Porto from the Deutsches Elektronen-Synchrotron DESY, has achieved a scientific breakthrough in high-precision analytic calculations for the relativistic two-body problem. The work, titled “Local-in-Time Conservative Binary Dynamics at Fifth Post-Minkowskian and First Self-Force Orders,” has been published in the prestigious journal Physical Review Letters.
The direct detection of gravitational waves has not only confirmed Einstein’s century-old prediction but has also opened a new window for exploring the universe. The mergers of binary compact objects—such as black holes and neutron stars—are the primary sources of current and future gravitational-wave observations. A precise understanding of their dynamics is therefore of great significance for deciphering the fundamental nature of gravity, constructing accurate gravitational waveform models, and leveraging gravitational-wave observations to address long-standing problems in fundamental physics.
Zhengwen Liu and his collaborators have produced a series of significant results in the analytical study of the relativistic two-body problem in recent years. Notably, in a 2024 study [Phys. Rev. Lett. 132 (2024) 221401], the team achieved, for the first time, the separation of local-in-time and non-local-in-time contributions in the scattering dynamics. This result removed a key obstacle to the analytic continuation of physical quantities between scattering and bound systems. In this latest work, the team extends this program to a new level of precision. Using methods from quantum field theory, they isolated the local-in-time sector from the full conservative dynamics and derived the analytic expression for the first self-force contribution at the fifth post-Minkowskian order. By combining these with the state-of-the-art post-Newtonian data, the team constructed the most accurate Hamiltonian to date describing the orbital motion of two-body systems.
This research markedly enhances the analytical precision of relativistic two-body dynamics. Such high-precision theoretical predictions are essential for next-generation gravitational-wave waveform modeling and for probing fundamental physics with observations.
Link: https://journals.aps.org/prl/abstract/10.1103/215k-27sj
