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 $\xi {\varphi }^{2}R$. Massless fields are coupled conformally at $\xi =1\mathrm{/}6$. Conformality can be preserved for fields of nonzero mass by shifting $\xi$. We discuss implications for density perturbations.