Nucl. Phys. B, 1019, 117111 (2025)

Note on post-Minkowskian expansion and Bondi coordinates

Pujian Mao and Baijun Zeng

Center for Joint Quantum Studies and Department of Physics, School of Science, Tianjin University, 135 Yaguan Road, Tianjin 300350, China.

* pjmao@tju.edu.cn, zeng@tju.edu.cn

Abstract

In this note, we transform the linear order (at order G) metric from a system of pointlike bodies source in the post-Minkowskian expansion to the Bondi coordinates. We show that the Bondi 4-momentum and angular momentum coincide with the relativistic definitions of 4-momentum and angular momentum for the system of pointlike bodies. The angular momentum computed at the null infinity is free of supertranslation ambiguity.