Published online by Cambridge University Press: 04 August 2017
Dissipationless formation mechanisms envisage elliptical galaxies as arising from the collective relaxation of an aggregate of stars. Their key ingredients are thus a set of initial conditions derived from consideration of prior evolution, and a treatment of the relaxation process. I review numerical studies of violent relaxation carried out over the last decade and purely theoretical treatments going back twice as far. Relaxation is always incomplete, and as a result the final structure of a “galaxy” depends sensitively on the initial conditions assumed. The viability of dissipationless formation thus rests on the identification of plausible stellar initial conditions which relax to the present structure. I discuss the extent to which such initial conditions are compatible with current ideas on the origin of structure in the universe.