Astrophysical tests of the nature of the dark matter

by Carlos Frenk, ICC Durham

The cold dark matter model predicts a mass function of halos and
subhalos that extends to masses comparable to the Earth. These halos
are predicted to have cuspy density profiles.  I will argue that
trying to test these predictions using halos large enough to have made
a galaxy (such as dwarfs galaxies and the satellites of the Milky Way)
is not conclusive. Instead one should focus on halos of such small
mass that they are unaffected by baryons. Such halos can be detected
from their gravitational lensing effects.