Numerical simulations have been a key player in our recent progresses in physical cosmology. Due to the non–linear nature of gravitational dynamics and gas physics, high–resolution, multi–scale schemes are now routinely used on massively parallel computers, to perform simulations of ever increasing size and complexity. With numerical simulations, the galaxy formation and evolution can be easily visualized.

 

   By comparison with observations, more precise physical parameters of the Universe can be estimated, and the theories on galaxy formation and evolution can be verified. In addition, predictions can be given for future observation to compare with. For example, the luminosity function of galaxies can be directly compared with predictions from cosmological simulations to verify the underlying physics imported in the simulation.