Extragalactic dark matter and direct detection experiments
  Recent astronomical data strongly suggest that a significant part of the dark
matter, composing the Local Group and Virgo Supercluster, is not incorporated
into the galaxy haloes and forms diffuse components of these galaxy clusters.
Apparently, a portion of the particles from these components may penetrate into
the Milky Way and make an extragalactic contribution to the total dark matter
containment of our Galaxy.
  We find that the particles of the diffuse component of the Local Group are
apt to contribute $\sim 12%$ to the total dark matter density near the Earth.
The particles of the extragalactic dark matter stand out because of their high
speed ($\sim 600$ {km/s}), i.e. they are much faster than the galactic dark
matter. In addition, their speed distribution is very narrow ($\sim 20$
{km/s}). The particles have isotropic velocity distribution (perhaps, in
contrast to the galactic dark matter). The extragalactic dark matter should
give a significant contribution to the direct detection signal. If the detector
is sensitive only to the fast particles ($v<450$ {km/s}), the signal may even
dominate.
  The density of other possible types of the extragalactic dark matter (for
instance, of the diffuse component of the Virgo Supercluster) should be
relatively small and comparable with the average dark matter density of the
Universe. However, these particles can generate anomaly high energy collisions
in direct dark matter detectors.
