Inflation in cosmological models with a nonminimally coupled, massless scalar field

Abstract

A homogeneous, spatially flat cosmological model induced by a massless scalar field is investigated. The parameter ξ of coupling of the field with the curvature can take any value. It is shown that the range of values of ξ is divided into three regions, ξ < 0, 0 < ξ < 1/6, and ξ > 1/6, each of which is characterized by the behavior of the scale factor in it. The points ξ = 0 and ξ= 1/6 are singular. Stages with exponential and power-law inflation are found in the ranges 0 < ξ < 1/6 and ξ > 1/6. An exponential inflationary stage with acceptable cosmological consequences can occur for small positive ξ. © 1997 Plenum Publishing Corporation.