Non-linear perturbations in multiple-field inflation
摘要
We develop a non-linear framework for describing long-wavelength perturbations in multiple-field inflation. The basic variables describing inhomogeneities are defined in a non-perturbative manner, are invariant under changes of time slicing on large scales and include both matter and metric perturbations. They are combinations of spatial gradients generalising the gauge-invariant variables of linear theory. Dynamical equations are derived and supplemented with stochastic source terms which provide the long-wavelength initial conditions determined from short-wavelength modes. Solutions can be readily obtained via numerical simulations or analytic perturbative expansions. The latter are much simpler than the usual second-order perturbation theory. Applications are given in a companion paper.
引用
@article{arxiv.astro-ph/0504508,
title = {Non-linear perturbations in multiple-field inflation},
author = {G. I. Rigopoulos and E. P. S. Shellard and B. J. W. van Tent},
journal= {arXiv preprint arXiv:astro-ph/0504508},
year = {2009}
}
备注
13 pages, no figures. v4: Included general form of equations of motion and constraints (before fixing gauge); minor textual changes. Matches published version