galaxy formation.

In recent years, HOD models have been introduced that make use of information about the positions, velocities and masses of halos and subhalos extracted from a dissipationless N-body simulation. The (sub)halo mass is then empirically linked to galaxy properties by requiring that a statistical observational quantity (e.g. galaxy luminosity function and/or galaxy two-point-correlation-function) is reproduced. This is either done by assuming parameterized functions to relate galaxy properties (such as luminosity) to halo mass or by assuming a non-parametric monotonic relation. It has been shown that these simple models reproduce galaxy clustering as a function of luminosity over a wide range in redshift [@kravtsov2004; @tasitsiomi2004; @tinker2005; @valeostriker06; @conroy06; @shankar2006; @wang06; @marin2008].

Observationally, it is well known that galaxy clustering is a function of spatial scale, galaxy properties (such as luminosity and type), and redshift. Luminous (massive) galaxies are more strongly clustered than less luminous (less massive) galaxies [@norberg2001; @norberg2002; @zehavi2002; @zehavi2005; @li06]. One can split the galaxy two-point correlation function (2PCF) into two separate parts: the one-halo and the two-halo terms. The one-halo term, which dominates on small scales, depends strongly on the galaxy distribution within the halo as well as the details of the HOD. The two-halo term, 