New exact solutions for inflationary cosmological perturbations

Abstract

From a general ansatz for the effective potential of cosmological perturbations we find new, exact solutions in single-scalar-field inflation: a three parameter family of exact inflationary solutions that encompasses all exact solutions that have been known previously (power-law inflation, Easther's model, and a generalised version of Starobinsky's solution). The main feature of this new family is that the spectral indices are scale dependent.

Comments: 12 pages, 5 figures, introduction improved, references added, accepted for publication in Phys. Lett. B