On the initial condition of inflationary fluctuations

Abstract

It is usually assumed that the inflationary fluctuations start from the Bunch-Davies (BD) vacuum and the $i\epsilon$ prescription is used when interactions are calculated. We show that those assumptions can be verified explicitly by calculating the loop corrections to the inflationary two-point and three-point correlation functions. Those loop corrections can be resumed to exponential factors, which suppress non-BD coefficients and behave as the $i\epsilon$ factor for the case of the BD initial condition. A new technique of loop chain diagram resummation is developed for this purpose. For the non-BD initial conditions which is setup at finite time and has not fully decayed, explicit correction to the two-point and three-point correlation functions are calculated. Especially, non-Gaussianity in the folded limit is regularized due to the interactions.

37 pages, 11 figures, an extension of previous work http://arxiv.org/abs/1507.05193

References in corpus (3)

• Observational Signatures and Non-Gaussianities of General Single Field Inflation
• Primordial Non-Gaussianities from Inflation Models
• Folded Resonant Non-Gaussianity in General Single Field Inflation

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