  Randall and Sundrum have proposed that we live on a brane embedded in
5-dimensional anti-deSitter space, as a solution to the hierarchy problem. We
examine the possibility of using a scalar field in the 5-D bulk as the
inflaton, and show that it gives results which are indistinguishable from an
inflaton which is restricted to our brane. This makes it difficult to get large
enough density perturbations in simple one-field inflationary models, since
mass scales on our brane are supposed to be limited by a cutoff of order 1 TeV.
