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arXiv · 1610.09943

Massless Interacting Scalar Fields in de Sitter space

Diana López Nacir·Francisco D. Mazzitelli·Leonardo G. Trombetta
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Abstract

We present a method to compute the two-point functions for an $O(N)$ scalar field model in de Sitter spacetime, avoiding the well known infrared problems for massless fields. The method is based on an exact treatment of the Euclidean zero modes and a perturbative one of the nonzero modes, and involves a partial resummation of the leading secular terms. This resummation, crucial to obtain a decay of the correlation functions, is implemented along with a double expansion in an effective coupling constant $\sqrt\lambda$ and in $1/N$. The results reduce to those known in the leading infrared approximation and coincide with the ones obtained directly in Lorentzian de Sitter spacetime in the large $N$ limit. The new method allows for a systematic calculation of higher order corrections both in $\sqrt\lambda$ and in $1/N$.

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Diana López Nacir, Francisco D. Mazzitelli, Leonardo G. Trombetta. 2016-10-31. Massless Interacting Scalar Fields in de Sitter space. https://doi.org/10.1051/epjconf%2F201612505019

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