Inflationary correlation functions without infrared divergences

M. Gerstenlauer, A. Hebecker, Gianmassimo Tasinato

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Inflationary correlation functions are potentially affected by infrared divergences. For example, the two-point correlator of curvature perturbation at momentum k receives corrections ~ ln (kL), where L is the size of the region in which the measurement is performed. We define infrared-safe correlation functions which have no sensitivity to the size L of the box used for the observation. The conventional correlators with their familiar log-enhanced corrections (both from scalar and tensor long-wavelength modes) are easily recovered from our IR-safe correlation functions. Among other examples, we illustrate this by calculating the corrections to the non-Gaussianity parameter fNL coming from long-wavelength tensor modes. In our approach, the IR corrections automatically emerge in a resummed, all-orders form. For the scalar corrections, the resulting all-orders expression can be evaluated explicitly.
Original languageEnglish
Pages (from-to)021
Number of pages1
JournalJournal of Cosmology and Astroparticle Physics
Issue number6
Publication statusPublished - Jun 2011


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