  The nonequilibrium steady state of a granular fluid, driven by a random
external force, is demonstrated to exhibit long range correlations, which
behave as $\sim 1/r$ in three and $\sim \ln(L/r)$ in two dimensions. We
calculate the corresponding structure factors over the whole range of wave
numbers, and find good agreement with two-dimensional molecular dynamics
simulations. It is also shown by means of a mode coupling calculation, how the
mean field values for the steady state temperature and collision frequency, as
obtained from the Enskog-Boltzmann equation, are renormalized by long
wavelength hydrodynamic fluctuations.
