Scalar fields around black hole binaries in LIGO-Virgo-KAGRA

Published 20 Oct 2025 in gr-qc, astro-ph.HE, and hep-ph | (2510.17967v1)

Abstract: Light scalar particles arise naturally in many extensions of the Standard Model and are well-motivated dark matter candidates. Gravitational interactions near black holes can trigger the growth of dense scalar configurations that, if sustained during inspiral, alter binary dynamics and imprint signatures on gravitational-wave signals. Detecting such effects would provide a novel probe of fundamental physics and dark matter. Here we develop a semi-analytic waveform model for binaries in scalar environments, validated against numerical relativity simulations, and apply it in a Bayesian analysis of the LIGO-Virgo-KAGRA catalog. Our results set physically meaningful upper bounds on scalar environments around compact binaries. When superradiance priors are included, we find tentative evidence for such an environment in GW190728 with $\ln B_{\mathrm{vac}}^{{\mathrm{env}}} \approx 3.5$, which would correspond to the existence of a light scalar field with mass $\sim 10^{{-12}\,\mathrm{eV}$.}