Long-Wavelength Modes of Cosmological Scalar Fields

We give a numerical analysis of long-wavelength modes in the WKB approximation of cosmological scalar fields coupled to gravity via $\xi\phi^{2}R$. Massless fields are coupled conformally at $\xi=1/6$. Conformality can be preserved for fields of nonzero mass by shifting $\xi$. We discuss implications for density perturbations.Comment: 10 pages, 10 figures, several stylistic improvement