Towards an Understanding of Galaxy Formation

Computer simulations have played a central role in defining the modern approach to physical cosmology. Simulations provide the means to calculate the formation history of cosmic structure, given a set of assumptions regarding the physics of the early universe and the values of the cosmological parameters. Several key concepts have been elaborated with the aid of N-body simulations. For example, the cold dark matter cosmogony and the attendant idea of biased galaxy formation - the focus of cosmological discussion during the 1990s - were first explored in detail in a series of N- body simulations1. Twenty years after the first cosmological N-body simulations were performed, this technique is now firmly established as the main theoretical tool for calculating the non-linear phases in the evolution of structure and for testing theories of the early universe against observational data.