  If cosmological cold dark matter (CDM) consists of light enough bosonic
particles that their phase-space density exceeds unity, they will comprise a
Bose-Einstein condensate (BEC). The nature of this BEC-CDM as a quantum fluid
may then distinguish it dynamically from the standard form of CDM involving a
collisionless gas of non-relativistic particles that interact purely
gravitationally. We summarize some of the dynamical properties of BEC-CDM that
may lead to observable signatures in galactic halos and present some of the
bounds on particle mass and self-interaction coupling strength that result from
a comparison with observed galaxies.
