Distribution functions for cuspy dark matter density profiles

Various analytic expressions have been proposed for the density profile of dark matter halos. We consider six of these expressions for which the densi ty profile has a power-law falloff rho proportional to r(-3) at large radii and a power-law cusp rho proportional to r(-gamma) (gamma = 0, 1/2, 1, 3/2 ) at small radii. The phase-space distribution function for these models is calculated assuming spherical symmetry and either an isotropic velocity di spersion tensor or an anisotropic dispersion tensor of the type proposed by Osipkov and Merritt. The differential energy distribution for these models is also derived. Several applications are discussed, including the analysi s of dark matter search experiments and the study of halo formation in a co smological setting. Analytic fitting formulae for some of the models are pr ovided.