This program, to be carried out by one of the world's leading theoretical astrophysicists, seeks to break new ground in the study of large-scale cosmic structure, and of the infall of matter onto compact objects. It will do this by implementing modern grid-based hydrocodes, to be adapted from successful aerodynamic codes. Previous work in cosmological modeling has been based primarily on sophisticated N-body codes, which, while adequate for studying dark matter, are less well adapted to observable gaseous matter. True hydrodynamic computational methods will be developed, which can treat shocks and radiative processes, and permit the direct calculation of X-ray emission, fluctuations in the cosmic background radiation, and other phenomena not accessible from the N-body approach.