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arXiv · 2609.35771

From Density to Mass: A New Parametrized Framework for Dark Matter Environment Around Black Holes

Rajes Ghosh·Nicholas Speeney·Avijit Chowdhury·Chiranjeeb Singha·Miguel A. S. Pinto·Emanuele Berti
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Abstract

Astrophysical black holes (BHs) are not isolated vacuum objects but are expected to reside within complex environments, such as dark matter (DM) halos and baryonic distributions. Such environments can modify the spacetime geometry surrounding the BH and leave observable imprints on gravitational-wave (GW) signals, including shifts in the quasinormal mode (QNM) spectrum, tidal Love numbers (TLNs), and the inspiral dynamics of extreme-mass-ratio inspirals (EMRIs). We develop a general framework for describing DM-dressed BH spacetimes by parameterizing the geometry directly in terms of the enclosed mass function, rather than the traditional density-based profile. This mass-based formulation is naturally connected to the total gravitational field, accommodates several common halo profiles as limiting cases, and incorporates basic physical consistency requirements such as regularity, causality, and appropriate asymptotic behavior. Within this framework, we investigate the environmental imprints on QNMs, TLNs, and GW fluxes from EMRIs. We find a complementary sensitivity to the halo structure: QNMs predominantly probe the inner regions of the environment, whereas static TLNs are more sensitive to its outer structure. EMRI fluxes, in contrast, probe the matter distribution through its influence on the orbital motion and GW propagation. Our results establish the enclosed-mass formulation as a flexible and physically controlled framework for connecting astrophysical environment models with precision GW observables.

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Rajes Ghosh, Nicholas Speeney, Avijit Chowdhury, Chiranjeeb Singha, Miguel A. S. Pinto, Emanuele Berti. 2026-09-28. From Density to Mass: A New Parametrized Framework for Dark Matter Environment Around Black Holes. https://arxiv.org/abs/2609.35771

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