Dynamical models and numerical simulations of incomplete violent   relaxation
  N-body simulations of collisionless collapse have offered important clues to the construction of realistic stellar dynamical models of elliptical galaxies. Such simulations confirm and quantify the qualitative expectation that rapid collapse of a self-gravitating collisionless system, initially cool and significantly far from equilibrium, leads to incomplete relaxation. In this paper we revisit the problem, by comparing the detailed properties of a family of distribution functions derived from statistical mechanics arguments to those of the products of collisionless collapse found in N-body simulations. 
M. Trenti (1), G. Bertin (2), ((1) Scuola Normale Superiore Pisa   Italy, (2) Dipartimento di Fisica Universita' di Milano I...