Measuring Bulk Flows in Large Scale Surveys

We follow a formalism presented by Kaiser to calculate the variance of bulk flows in large scale surveys. We apply the formalism to a mock survey of Abell clusters 'a la Lauer & Postman and find the variance in the expected bulk velocities in a universe with CDM, MDM and IRAS–QDOT power spectra. We calculate the velocity variance as a function of the 1–D velocity dispersion of the clusters and the size of the survey.