Galaxy formation - Some comparisons between theory and observation

The present investigation is mainly concerned with theories which are based on some form of hierarchical clustering because the pancake and related theories are not yet refined enough for a detailed confrontation with observations. The considered approach involves the exploration of the consequences of relaxing in succession the constraints that the energy E, the angular momentum J, and the total mass M be conserved during the collapse of protogalaxies. A hierarchy under conditions in which E, J, and M are conserved is considered along with a hierarchy involving a dissipated E, while J and M are conserved. Attention is also given to a hierarchy with E dissipated and J and M stripped.