Halo Abundance Matching (HAM) is a method of comparing
observation and theory regarding galaxies and their
Dark Matter Halos. Cosmological models and simulations
yield a certain mass distribution of halos and galaxy
Surveys yield a luminosity distribution of galaxies.
The distributions may show a correspondence suggesting
a relation between halo mass and its galaxy's Luminosity,
or alternately, correspondence can be taken as a test
of the accuracy of the Dark Matter theory or the galaxy observations.