Collective excitations of self-gravitating ultralight dark matter cores

Abstract

A distinctive feature of ultralight bosonic dark matter is its ability to form a Bose–Einstein condensate with a dense, stationary configuration at the center of galactic halos. In this work, we investigate the internal dynamics of such cores by numerically solving the Bogoliubov–de Gennes equations within a fully self-consistent gravitational framework, accounting for both gravitational potential perturbations and local self-interactions. We demonstrate that the solitonic core supports a discrete spectrum of well-defined collective modes. These oscillations characterize the linear response of the core to perturbations and may influence various dynamical processes. We also discuss potential astrophysical implications of these excitations on galactic scales.