  N-body simulations of structure formation with scale-invariant primordial
perturbations show significantly more virialized objects of dwarf-galaxy mass
in a typical galactic halo than are observed around the Milky Way. We show that
the dearth of observed dwarf galaxies could be explained by a dramatic downturn
in the power spectrum at small distance scales. This suppression of small-scale
power might also help mitigate the disagreement between cuspy simulated halos
and smooth observed halos, while remaining consistent with Lyman-alpha-forest
constraints on small-scale power. Such a spectrum could arise in inflationary
models with broken scale invariance.
