  For physicists, recent developments in astrophysics and cosmology present
exciting challenges. We are conducting "experiments" in energy regimes some of
which will be probed by accelerators in the near future, and others which are
inevitably the subject of more speculative theoretical investigations. Dark
matter is an area where we have hope of making discoveries both with
accelerator experiments and dedicated searches. Inflation and dark energy lie
in regimes where presently our only hope for a fundamental understanding lies
in string theory.
