Black Holes as Condensation Points of Fuzzy Dark Matter Cores

TL;DR

This paper demonstrates through simulations that black holes can act as seeds for fuzzy dark matter core formation, influencing core density based on black hole mass and providing a new phenomenological density formula.

Contribution

It introduces a novel simulation approach showing black holes as focal points for fuzzy dark matter core condensation, and derives a phenomenological density formula for FDM cores around black holes.

Findings

Black holes can serve as seeds for FDM core condensation.

The central density of FDM cores depends on black hole mass.

A new phenomenological formula for FDM density around black holes.

Abstract

We simulate the formation of Fuzzy Dark Matter (FDM) cores in the presence of a Black Hole (BH) to explore whether BHs can serve as seeds for FDM core condensation. Our analysis is based on the core-condensation via the kinetic relaxation process for random initial conditions of the FDM. In a generic scenario the BH merges with a pre-collapsed mini-cluster formed in a random location, once they share location the core-condensation starts withe the FDM density centered at the black hole that during the process acquires a profile consistent with that of the stationary solution of the FDM+BH eigenvalue problem. These results indicate that BHs can indeed act as focal points for FDM core condensation. Furthermore, we find that the central density of the resulting FDM core depends on the mass of the BH, which due to its permanent motion relative to the FDM core during the evolution, produces a smaller core density for bigger BH masses; in this way the BH mass is a parameter leading to a new diversity of central FDM core densities. As a collateral result, for our analysis we revised the construction of stationary solutions of FDM+BH and found a phenomenological formula for the FDM density that can be used to fit FDM cores around BHs.