Generalized slow-roll conditions and the possibility of intermediate scale inflation in scalar-tensor theory (Q2752508)

The author discusses the generalized slow-roll conditions and parameters for a scalar-tensor theory having no external sources. More precisely, the theory includes functions describing a non-minimal gravitational coupling \(F(\phi)\), a Kähler-like kinetic function \(k(\phi)\), and a scalar potential \(V(\phi)\). It is then employed to analyse a simple toy model of chaotic inflation having a single scalar field \(\phi\), and a standard Higgs potential with a simple gravitational coupling function. It is shown that inflation can occur with intermediate inflation values in the Jordan frame, whereas in the Einstein frame such inflation does not occur. Contents include: an introduction; the scalar-tensor theory; generalized slow-roll conditions and parameters; intermediate scale chaotic inflation; the Jordan and Einstein conformal frames; summary and concluding remarks; and an appendix on the slow-roll equations of motion.