Oscillations and random walk of the soliton core in a fuzzy dark matter halo

A fuzzy dark matter halo consists of a soliton core close to the center and a Navarro-Frenk-White-like density profile in the outer region. Previous investigations found that the soliton core exhibits temporal oscillations and random walk excursions around the halo center. Analyzing a set of numerical simulations, we show that both phenomena can be understood as the results of wave interference-a suitable superposition of the ground (solitonic) state and excited states in a fixed potential suffices to account for the main features of these phenomena. Such an eigenmode analysis can shed light on the evolution of a satellite halo undergoing tidal disruption. As the outer halo is stripped away, reducing the amplitudes of the excited states, the ground state evolves adiabatically. This suggests diminished soliton oscillations and random walk excursions, an effect to consider in deducing constraints from stellar heating.

Automated summary

It has been found that a fuzzy dark matter halo consists of a soliton core and a density profile, with the soliton core showing temporal oscillations and random walk excursions that can be explained by wave interference. Analysis of numerical simulations reveals that these phenomena are mainly due to a suitable superposition of the ground state and excited states. This eigenmode analysis sheds light on the evolution of a satellite halo undergoing tidal disruption.