Multicomponent de Sitter (inflationary) stages and the generation of perturbations
Starobinskii A. A.
General formulas are derived for the degree of expansion of the universe and for the amplitude of adiabatic perturbations generated by the quantum fluctuations in the de Sitter (inflationary) stage which is produced by the combined action of an arbitrary number of scalar fields with different potentials and the quantum-gravitational correction (oc R 2) to the Lagrangian.