In recent years there has been a great expansion of knowledge of the large scale structure of the universe. The acquisition of large sets of high quality astronomical data, coupled with the availability of increasingly powerful supercomputers, has transformed the subject of the origin and evolution of structure in the universe profoundly. Models for the growth of structure incorporating Particle Physics candidates for the dark matter in the universe can now be confronted with detailed observational data. To study the critical non-linear evolutionary epochs in the universe requires three-dimensional many particle simulations with large dynamic range. The PI has developed a hierarchical N-body code with much improved dynamic range in both length and mass, and which is also much faster than previously available codes. This will be used to investigate the evolution of structure in an expanding universe containing cold dark matter.