The Velocity Field Around Groups of Galaxies
  A statistical method is presented for determining the velocity field in the
immediate vicinity of groups of galaxies using only positional and redshift
information with the goal of studying the perturbation of the Hubble flow
around groups more distant than the Local Group. The velocities are assumed to
obey a Hubble-like expansion law, i.e. $V=H_{exp}R$ where the expansion rate
$H_{exp}$ is to be determined. The method is applied to a large, representative
group catalog and evidence is found for a sub-Hubble expansion rate within two
well defined radii beyond the virial radii of the groups. This result is
consistent with that of Teerikorpi et al. (2008) who found a similar expansion
law around 3 nearby groups and extends it to a more representative volume of
space.
