Using Galaxy Cluster Peculiar Velocities to Constrain Cosmological   Parameters
  Galaxy cluster peculiar velocities can be inferred from high-sensitivity, high-resolution multiple-frequency observations in the 30 to 400 GHz range. While galaxy cluster counts and power spectra are sensitive to the growth factor, peculiar velocities are sensitive to the time-derivative of the growth factor and are hence complementary. Using linear perturbation theory, we forecast constraints on Omega(matter), the Hubble constant today, and the dark-energy equation of state parameter, given 820 densely sampled cluster locations (near redshift 1) from a Lambda-CDM N-body simulation and 820 sparsely sampled cluster locations in a broader redshift range. 
A. Peel, L. Knox (UC Davis)