http://arxiv.org/abs/1811.03216
The effective field theory (EFT) of inflation provides a natural framework to study the new physical effects on primordial perturbation spectrum that is original from the higher derivative terms of the theory. Recently a healthy combination of high order operators has been formulated in an extension of the EFT of inflation, which allows one to avoid ghosts and leads to nonlinear dispersion relation for scalar perturbations. This paper devotes to study the new physics effects of these high order operators in primordial perturbations in this extended EFT of inflation by using the uniform asymptotic approximation method. For this purpose, we first construct the approximate and analytical solution of the mode functions for scalar perturbations. Because of the presence of the high order operators in the extended EFT of inflation, the perturbation modes may experience a period of non-adiabatic evolution before it crosses Hubble horizon. We show that it is these high order operators that may lead to the production of excited states and modifications of primordial perturbation spectrum. In particular, after deriving analytically the impact of these new effects on particle production rate and perturbation spectrum, we explain in details for different origins of these new effects.
J. Qiao, G. Ding, Q. Wu, et. al.
Fri, 9 Nov 18
20/64
Comments: 13 pages, 5 figures