Massless Interacting Scalar Fields in de Sitter space

EPJ Web of Conferences. 2016;125:05019 DOI 10.1051/epjconf/201612505019

 

Journal Homepage

Journal Title: EPJ Web of Conferences

ISSN: 2100-014X (Online)

Publisher: EDP Sciences

LCC Subject Category: Science: Physics

Country of publisher: France

Language of fulltext: English

Full-text formats available: PDF

 

AUTHORS

Nacir Diana López (Theoretical Physics Department, CERN)
Mazzitelli Francisco D. (Centro Atómico Bariloche and Instituto Balseiro, CONICET, Comisión Nacional de Energía Atómica)
Trombetta Leonardo G. (Centro Atómico Bariloche and Instituto Balseiro, CONICET, Comisión Nacional de Energía Atómica)

EDITORIAL INFORMATION

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Time From Submission to Publication: 6 weeks

 

Abstract | Full Text

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 √λ 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 √λ and in 1/N.