Analytical galactic models with mild stellar cusps
  In the past two decades, it has been established by high-resolution
observations of early-type galaxies that their nuclear surface brightness and
corresponding stellar mass densities are characterized by cusps. In this paper,
we present a new spherical analytical model family describing mild cuspy
centres. We study isotropic and anisotropic models of Osipkov-Merritt type. It
is shown that the associated distribution functions and intrinsic velocity
dispersions can be represented analytically in a unified way in terms of
hypergeometric series, allowing thus a straightforward comparison of these
important global quantities for galaxies having underlying mass densities which
may differ significantly in their degree of central cuspiness or radial
falloff.
