SLOW-ROLL INFLATION IN SCALAR TENSOR THEORIES

The slow-roll approximation is specified for cosmological models in scalar-tensor gravity theories. Specific isotropic cosmological models with zero curvature are found for the class of theories in which the gravitational coupling function ω(cphi) is a power-law function of the gravitational scalar field cphi when the Universe contains other scalar fields with constant, power-law, and exponential potentials, respectively. Some new types of inflation are found, but intermediate inflationary behavior is displayed by a wide class of models. © 1995 The American Physical Society.