1 research outputs found
Non-linear inflationary perturbations
We present a method by which cosmological perturbations can be quantitatively
studied in single and multi-field inflationary models beyond linear
perturbation theory. A non-linear generalization of the gauge-invariant
Sasaki-Mukhanov variables is used in a long-wavelength approximation. These
generalized variables remain invariant under time slicing changes on long
wavelengths. The equations they obey are relatively simple and can be
formulated for a number of time slicing choices. Initial conditions are set
after horizon crossing and the subsequent evolution is fully non-linear. We
briefly discuss how these methods can be implemented numerically in the study
of non-Gaussian signatures from specific inflationary models.Comment: 10 pages, replaced to match JCAP versio