Annu. Rev. Astron. Astrophys. 1998. 36: 599-654 Copyright © 1998 by Annual Reviews. All rights reserved

6. FUTURE DIRECTIONS

Ten years ago, the field of computational cosmology was in something of a doldrums, with the standard CDM model reeling and rather little to replace it. The experience brought valuable lessons to the field and encouraged new ideas and applications. Now simulations are used to provide invaluable insight into physical systems such as quasar absorption lines, despite our lack of a definite structure formation model.

During the next decade, simulations will be applied toward investigation of the leading outstanding questions in cosmology, such as the following. What are the values of the cosmological parameters? What is the dark matter and how much is there? What was the nature of the primordial density fluctuations? How different are the galaxy and mass density fields? When did galaxies and clusters of galaxies form? Why is galaxy morphology different in rich clusters from lower-density environments? What are the best ways to analyze the new large redshift surveys and other datasets that will become available?

Addressing many of these questions more rigorously than heretofore will require more physics and higher resolution than are available in current-generation simulations. Significant steps have been taken already with inclusion of multispecies chemistry in several gas dynamics codes. Improved treatments of radiative transfer and energy feedback through star formation will be required. In some environments, e.g. clusters of galaxies, inclusion of magnetic fields may be desirable. Yet for many problems, the limiting factor remains resolution. Gradually, this limitation will recede with the combination of adaptive algorithms and the relentless speedup of computers. Students wishing to enter this field will benefit from a broad background in physical processes, numerical algorithms, and high-performance computing in addition to astrophysics and cosmology.

ACKNOWLEDGMENTS

I gratefully acknowledge support from the National Science Foundation under grants AST-9318185 and AST-9529154 and from the National Aeronautics and Space Administration under grant NAG5-2816.