Inflationary perturbation spectrum in extended effective field theory of inflation. (arXiv:1811.03216v1 [hep-th])

Inflationary perturbation spectrum in extended effective field theory of inflation. (arXiv:1811.03216v1 [hep-th])
<a href="http://arxiv.org/find/hep-th/1/au:+Qiao_J/0/1/0/all/0/1">Jin Qiao</a>, <a href="http://arxiv.org/find/hep-th/1/au:+Ding_G/0/1/0/all/0/1">Guang-Hua Ding</a>, <a href="http://arxiv.org/find/hep-th/1/au:+Wu_Q/0/1/0/all/0/1">Qiang Wu</a>, <a href="http://arxiv.org/find/hep-th/1/au:+Zhu_T/0/1/0/all/0/1">Tao Zhu</a>, <a href="http://arxiv.org/find/hep-th/1/au:+Wang_A/0/1/0/all/0/1">Anzhong Wang</a>

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.

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.

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