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Accurate determination of inflationary perturbations

Ian J Grivell·Andrew R Liddle
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Abstract

We use a numerical code for accurate computation of the amplitude of linear density perturbations and gravitational waves generated by single-field inflation models to study the accuracy of existing analytic results based on the slow-roll approximation. We use our code to calculate the coefficient of an expansion about the exact analytic result for power-law inflation; this generates a fitting function which can be applied to all inflationary models to obtain extremely accurate results. In the appropriate limit our results confirm the Stewart--Lyth analytic second-order calculation, and we find that their results are very accurate for inflationary models favoured by current observational constraints.

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Ian J Grivell, Andrew R Liddle. 1996-07-18. Accurate determination of inflationary perturbations. https://doi.org/10.1103/physrevd.54.7191

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