Formation and Redshift Evolution of Dark Matter Spikes

Fuente: arXiv
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Hauptverfasser: Herrera, Gonzalo, Hussein, Abdelaziz, Necib, Lina, Davies, Elliot Y., Shen, Xuejian
Format: Preprint
Veröffentlicht: 2026
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author Herrera, Gonzalo
Hussein, Abdelaziz
Necib, Lina
Davies, Elliot Y.
Shen, Xuejian
author_facet Herrera, Gonzalo
Hussein, Abdelaziz
Necib, Lina
Davies, Elliot Y.
Shen, Xuejian
contents Dark matter density spikes forming around adiabatically growing black holes can dramatically enhance indirect and direct detection signals. Canonical predictions, however, assume a zero-mass seed in a purely dark matter environment and do not track the long-term dynamical impact of surrounding stars. We present a semi-analytic framework that first generalizes adiabatic spike formation to include finite seed masses, stellar cusps, and non-circular orbits, and then studies the subsequent cosmic evolution by solving coupled Fokker-Planck equations for the dark matter and stellar phase-space distributions, with a heating rate modulated by the cosmic star formation rate. Starting conservatively from canonical Gondolo-Silk spikes and marginalizing over astrophysical uncertainties, we find that stellar gravitational heating drives the inner slope towards $γ_χ\simeq 1.5$ within a few Gyrs (e.g by $z \lesssim 2$ for spikes formed at $z\simeq 10$), yielding overdensities two to four orders of magnitude below canonical expectations but still well above an NFW-like cusp. We provide redshift-dependent benchmarks for the column density and $J$-factor relevant to scattering, decay and annihilation signatures. Any robust interpretation of indirect dark matter signals from galactic nuclei must account for this evolution.
format Preprint
id arxiv_https___arxiv_org_abs_2605_01023
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Formation and Redshift Evolution of Dark Matter Spikes
Herrera, Gonzalo
Hussein, Abdelaziz
Necib, Lina
Davies, Elliot Y.
Shen, Xuejian
Cosmology and Nongalactic Astrophysics
High Energy Astrophysical Phenomena
General Relativity and Quantum Cosmology
High Energy Physics - Phenomenology
Dark matter density spikes forming around adiabatically growing black holes can dramatically enhance indirect and direct detection signals. Canonical predictions, however, assume a zero-mass seed in a purely dark matter environment and do not track the long-term dynamical impact of surrounding stars. We present a semi-analytic framework that first generalizes adiabatic spike formation to include finite seed masses, stellar cusps, and non-circular orbits, and then studies the subsequent cosmic evolution by solving coupled Fokker-Planck equations for the dark matter and stellar phase-space distributions, with a heating rate modulated by the cosmic star formation rate. Starting conservatively from canonical Gondolo-Silk spikes and marginalizing over astrophysical uncertainties, we find that stellar gravitational heating drives the inner slope towards $γ_χ\simeq 1.5$ within a few Gyrs (e.g by $z \lesssim 2$ for spikes formed at $z\simeq 10$), yielding overdensities two to four orders of magnitude below canonical expectations but still well above an NFW-like cusp. We provide redshift-dependent benchmarks for the column density and $J$-factor relevant to scattering, decay and annihilation signatures. Any robust interpretation of indirect dark matter signals from galactic nuclei must account for this evolution.
title Formation and Redshift Evolution of Dark Matter Spikes
topic Cosmology and Nongalactic Astrophysics
High Energy Astrophysical Phenomena
General Relativity and Quantum Cosmology
High Energy Physics - Phenomenology
url https://arxiv.org/abs/2605.01023