Galactic Condensates composed of Multiple Axion Species
  Ultralight scalar dark matter has been proposed to constitute a component of
dark matter, though the minimal scenarios have increasingly become constrained.
In this work, we analyze scenarios where the dark matter consists of more than
one ultralight boson, each with different masses. This potentially leads to
formation of gravitationally-bound Bose-Einstein condensates with structures
that are very different from condensates composed of a single scalar field. By
generalizing from the well-understood single-flavor case, we explore a large
range of input parameters, subject to stability criteria, and determine the
allowed parameter space for two-flavor condensates as a function of particle
physics parameters, paying particular attention to cases where such condensates
could compose galactic cores. We also analyze single-flavor condensates subject
to external gravity from massive inner bodies and find that such systems may
mimic the size of galactic cores as well.
