Mike Hudson
Waterloo

Beyond the Great Attractor: Probing Dark Matter with Cosmic Flows


Cosmic flows --- deviations from the uniform expansion -- are the only
probe of the large-scale distribution of dark matter in the nearby
Universe.  Twelve years ago, the "Seven Samurai" claimed the existence
of a large mass concentration -- the "Great Attractor" -- which they
argued was responsible for most of the Local Group's peculiar motion
with respect to the Cosmic Microwave Background. Since then there have
been a number of observational surveys designed to probe the
large-scale mass distribution.  Results from these new surveys will be
reviewd, focussing on our recently-completed SMAC survey of clusters.
The latter has yielded a large bulk motion over very large scales. I
will describe the implications of this surprising result for
currently-popular cosmological models.