The 2PN Point-Mass N-Body Equations of Motion in Harmonic Gauge: A Computable Formulation
Abstract
We develop a semi-analytic and semi-numerical formulation of the harmonic-gauge second post-Newtonian (2PN) equations of motion for a general point-mass N-body system within Hadamard regularization. The equations of motion are separated into a closed analytic contribution and a non-closed integral contribution. We analyze the singular structure of the latter and further regularize it into a numerically evaluable representation. We apply the formulation to the Sun-Jupiter-Saturn and Sun-Mercury-Venus systems, evaluating the instantaneous non-closed 2PN acceleration along Newtonian trajectories and its leading finite-time relative-distance response through the corresponding perturbation equations. In both benchmarks, the non-closed acceleration remains a small fraction of the complete 2PN acceleration, while the induced relative-distance perturbation remains oscillatory and can reach larger oscillation amplitudes at later times.
Related
- Run-and-tumble particles in a harmonic external field: constructing the solution of the Fokker-Planck equation from the equations of motion
- Non-stationary Statistics and Energetics of Brownian Motion under Stochastic Harmonic Confinement
- On the Motion of a Point Electric Charge in the Field of Wu-Yang Monopoles in Bertotti-Robinson Spacetimes
- Exact Solutions of Maxwell Vacuum Equations in Null Homogeneous Petrov Spaces with Non-Solvable Motion Groups
- Extensions to the Navier-Stokes-Fourier Equations for Rarefied Transport: Entropy Variable Formulation, Heat Transfer and Dispersion of a Non-Linear Entropy Stable Closure
BibTeX
@misc{huang2026pointmass,
title = {{The 2PN Point-Mass N-Body Equations of Motion in Harmonic Gauge: A Computable Formulation}},
author = {Hongkun Huang and Jie Yang and Wei-Tou Ni},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2608.20193},
eprint = {2608.20193},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.20193},
}
RIS
TY - UNPB
TI - The 2PN Point-Mass N-Body Equations of Motion in Harmonic Gauge: A Computable Formulation
AU - Hongkun Huang
AU - Jie Yang
AU - Wei-Tou Ni
PY - 2026
DA - 2026/09/10
PB - arXiv
DO - 10.48550/arxiv.2608.20193
UR - https://arxiv.org/abs/2608.20193
AB - We develop a semi-analytic and semi-numerical formulation of the harmonic-gauge second post-Newtonian (2PN) equations of motion for a general point-mass N-body system within Hadamard regularization. The equations of motion are separated into a closed analytic contribution and a non-closed integral contribution. We analyze the singular structure of the latter and further regularize it into a numerically evaluable representation. We apply the formulation to the Sun-Jupiter-Saturn and Sun-Mercury-Venus systems, evaluating the instantaneous non-closed 2PN acceleration along Newtonian trajectories and its leading finite-time relative-distance response through the corresponding perturbation equations. In both benchmarks, the non-closed acceleration remains a small fraction of the complete 2PN acceleration, while the induced relative-distance perturbation remains oscillatory and can reach larger oscillation amplitudes at later times.
ER -