Oscillations and random walk of the soliton core in a fuzzy dark matter halo
Abstract
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.
Type
Publication
Physical Review D
Authors
Assistant Professor
Xinyu Li is an assistant professor in the Department of Astronomy, Tsinghua University. He is fond of discovering fundamental physical laws from the vast observation of various astrophysical objects. His research areas are high energy astrophysics, plasma astrophysics and cosmology. His research topics cover a broad range of physical scales: from the smallest fundamental particles like electrons and ultralight axions, to neutron stars, black holes and galaxies, and to the largest scale structure of the universe.