Classical gravitational scattering with a massive scalar mediator
Abstract
We consider the classical scattering of two gravitating compact objects in the presence of a massive scalar mediator, providing a simple model of exotic phenomena. Through dimensional analysis, we argue that such a process can only be classical in the presence of gravity, a consequence of which is that perturbing in the coupling of the scalar to a worldline is not separate from the post-Minkowskian expansion. When computing asymptotic observables, the massive mediator complicates the Fourier transforms to impact-parameter space at next-to-leading order. We reduce these to univariate parametric integrals - amenable to numerical integration - and produce analytic results for the linear impulse and the scattering angle to the second post-Minkowskian order. The scattering angle exhibits a maximum when the range of the scalar-mediated force is comparable to the impact parameter, a possible signature of a massive scalar mediator. In the opposite, large-mass regime we uncover a screening effect: integrating out the scalar sourced by each compact object reduces its gravitational mass by an amount linear in the scalar's mass. Both of these phenomena are next-to-leading-order effects.
Related
- Elastic Scattering of Dirac Dark Matter with Charged Leptons through a Scalar Mediator: Analytical Framework, Numerical Stability, and Direct-Detection Bounds
- Relativistic Elastic Scattering of Cosmic-Ray Boosted Dirac Dark Matter with Charged Leptons through a Scalar Mediator
- Gravitational Radiation Coupled to a real massive scalar Field
- Classical and quantum scattering of massive Klein--Gordon fields in asymptotically flat spacetimes
- Absorption and scattering spectra of massive scalar waves in charged regular black hole spacetimes
BibTeX
@misc{biendarra2026classical,
title = {{Classical gravitational scattering with a massive scalar mediator}},
author = {Birgitta Biendarra and Kays Haddad and Jan Plefka},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2608.14267},
eprint = {2608.14267},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.14267},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Classical gravitational scattering with a massive scalar mediator
AU - Birgitta Biendarra
AU - Kays Haddad
AU - Jan Plefka
PY - 2026
DA - 2026/09/23
PB - arXiv
DO - 10.48550/arxiv.2608.14267
UR - https://arxiv.org/abs/2608.14267
AB - We consider the classical scattering of two gravitating compact objects in the presence of a massive scalar mediator, providing a simple model of exotic phenomena. Through dimensional analysis, we argue that such a process can only be classical in the presence of gravity, a consequence of which is that perturbing in the coupling of the scalar to a worldline is not separate from the post-Minkowskian expansion. When computing asymptotic observables, the massive mediator complicates the Fourier transforms to impact-parameter space at next-to-leading order. We reduce these to univariate parametric integrals - amenable to numerical integration - and produce analytic results for the linear impulse and the scattering angle to the second post-Minkowskian order. The scattering angle exhibits a maximum when the range of the scalar-mediated force is comparable to the impact parameter, a possible signature of a massive scalar mediator. In the opposite, large-mass regime we uncover a screening effect: integrating out the scalar sourced by each compact object reduces its gravitational mass by an amount linear in the scalar's mass. Both of these phenomena are next-to-leading-order effects.
ER -