Second Moment of Halo Occupation Number

The halo approach to large-scale structure provides a physically motivated model to understand the clustering properties of galaxies. An important aspect of the halo model involves a description of how galaxies populate dark matter halos or what is now called the halo occupation distribution. We discuss a way in which clustering information, especially in the nonlinear regime, can be used to determine moments of this halo occupation number. We invert the nonlinear part of the real space power spectrum from the IRAS Point Source Catalog galaxy redshift survey to determine the second moment of the halo occupation distribution in a model-independent manner. The precise measurement of higher order correlations can eventually be used to determine successive higher order moments of this distribution.