Dynamical Friction in Cuspy Galaxies
  It is well known that a large fraction of galaxies have cuspy luminosity profiles in their central regions, at least within the observational resolution. In such cases, the often used, simplified, local approximation for the dynamical friction braking classical term fails when the massive satellite moves through the inner parts of the galaxy, although the scattering integral still converges for phase space distribution singularities that are not too sharp. Here we present preliminary results of our work aiming at finding better and more reliable results from the integration of motion of massive objects (globular clusters) in galaxies where the density diverges to the center in a power law form, with exponent greater than -2. 
M. Arca-Sedda and R. Capuzzo-Dolcetta (Dep. of Physics, "Sapienza",   Universita' di Roma, Roma, Italy)
astro-ph.GA