| Issue |
A&A
Volume 703, November 2025
|
|
|---|---|---|
| Article Number | A68 | |
| Number of page(s) | 12 | |
| Section | Numerical methods and codes | |
| DOI | https://doi.org/10.1051/0004-6361/202555656 | |
| Published online | 07 November 2025 | |
Numerical solutions of the complete two-body system in QUMOND
Helmholtz-Institut für Strahlen- und Kernphysik,
Nussallee 14–16,
53115
Bonn,
Germany
★ Corresponding author: jpa@hiskp.uni-bonn.de
Received:
25
May
2025
Accepted:
14
August
2025
Context. Due to the non-linearity of the QUMOND field equations, the current modelling of binaries replaces the two-body system with an effective one-body system, where the central particle contains the total mass of both binary components and is orbited by a massless test particle.
Aims. In this work, we quantify the discrepancy between the effective one-body treatment and the complete two-body solution in QUMOND.
Methods. Particles are treated as the limits of Dirac sequences. Thus, the QUMOND contribution to the total kinematical acceleration of a particle is expressed as a Green’s integral, which is calculated numerically.
Results. In the non-linear transition regime, the kinematical acceleration of the effective one-body system with a total mass of 2 M⊙ is up to a factor of 1.44 higher than the Newtonian acceleration; whereas the acceleration is only boosted by a factor of 1.2-1.3 in the two-body system when employing the simple transition function.
Key words: gravitation / methods: numerical / stars: kinematics and dynamics
© The Authors 2025
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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