Scalar dark matter vortex stabilization with black holes

Abstract

Galaxies and their dark-matter halos are commonly presupposed to spin. But it is an open question how this spin manifests in halos and soliton cores made of scalar dark matter (SDM, including fuzzy/wave/ultralight-axion dark matter). One way spin could manifest in a necessarily irrotational SDM velocity field is with a vortex. But recent results have cast doubt on this scenario, finding that vortices are generally unstable except with substantial repulsive self-interaction. In this paper, we introduce an alternative route to stability: in both (non-relativistic) analytic calculations and simulations, a black hole or other central mass at least as massive as a soliton can stabilize a vortex within it. This conclusion may also apply to AU-scale halos bound to the sun and stellar-mass-scale Bose stars.

UltraDark.jl: A Julia package for simulation of cosmological scalar fields

“…We have used UltraDark.jl to explore tidal disruption in dark matter halos comprised of self-interacting ALPs (Glennon et al, 2022), the effects of self-interactions on dynamical friction (Glennon et al, 2024), perform the first simulations of multi-species ALPs with intraand inter-species interactions ) and discover a novel mechanism for vortex stabilisation in scalar dark matter (Glennon, Mirasola, Musoke, et al, 2023a). More sample output can be found in Glennon, Mirasola, Musoke, et al (2023b), Glennon, Musoke, Nadler, et al (2023).…”

Perspective Chapter: Squeezing and Entanglement of Two-Modes Quantum X Waves

“…[5]. Vortex solutions produced in some particle physics models like extended Abelian Higgs model [6], Galaxies and their dark-matter halos [7].…”