Speaker
Description
We present a solution of the Schrodinger–Poisson system based on the WKB
ansatz for the wave function. In this way we obtain a description of a gravitationally bound
clump of axion dark matter by a superposition of energy eigenstates with random phases. It
can be applied to any self-consistent pair of radial density distribution and phase space den-
sity f (E) related by Eddington’s formula. We adopt this as a model for axion miniclusters in
our galaxy and use it to study the mass loss due to a star encounter by using standard pertur-
bation theory methods known from quantum mechanics. Finally, we perform a Monte Carlo
study to estimate the surviving fraction of axion miniclusters in the dark matter halo of our
galaxy. We find that the reaction to perturbations and the survival probability depend cru-
cially on the density profile. Weakly bound clusters are heated up and eventually destroyed,
whereas more strongly bound systems get even more compact as a result of perturbations
and are driven towards an axion star configuration.
