Speaker
Description
Dark matter can form very steep density enhancements, or spikes, around black holes. Recent work has proposed that unusually rapid orbital‑period decay observed in two nearby black‑hole X‑ray binaries could be caused by such spikes. If confirmed in systems where current formation models do not predict them, this would imply far more widespread, dense dark‑matter structures than expected. We revisit these claims with N‑body simulations and include a third, previously unexamined system. Our simulations show that feedback effects substantially reshape the spikes, excluding the shallow density profiles suggested earlier; continued long‑term evolution may alter the spike further, underscoring the need for improved models of binaries embedded in dense dark‑matter environments.
| Main Contribution topic | Astrophysical observations |
|---|---|
| Secondary contribution topic | Cosmology Dark Matter |