Gravitational processes in galactic nuclei

Gravitational relaxation in galactic nuclei, and the redistribution of stars through gravithermal instability, evaporation, mass segregation and orbit segregation, are discussed. Violent relaxation occurs by scattering from ever-changing mean field fluctuations, and large-scale collective modes govern the early evolution of resulting galactic nuclei. Gentle relaxation, resulting from the small deflections of two-body scattering, operates during and after violent relaxation, and depends completely on the graininess of the mass distribution. As a first approximation, both types of relaxation lead to a Maxwell-Boltzmann distribution.