Gravity-scalar fluctuations in holographic RG flow geometries

We study five-dimensional gravity models with non-vanishing background scalar fields which are dual to non-conformal boundary field theories. We develop a procedure to decouple the graviton fluctuations from the scalar ones and apply it to the simplest case of one scaler field, The quadratic action for the decoupled scaler fluctuations has a very simple form and can be used to compute two-point functions. We perform this computation for the two examples of background RG now recently considered by DeWolfe and Freedman and find physically reasonable results. (C) 2000 Elsevier Science B.V. All rights reserved.