Year: 2008
Type: article
Abstract: It is well known that the correlation functions of a scalar field in a quasi-de Sitter space exhibit at the loop level cumulative infrared effects proportional to the total number of e-foldings of inflation. Using the in–in formalism, we explore the behavior of these infrared effects in the large N limit of an O( N )-invariant scalar field theory with quartic self-interactions. By resumming all higher-order loop diagrams non-perturbatively, we show that the connected four-point correlation function, which is a signal of non-Gaussianity, is non-perturbatively enhanced with respect to its tree-level value.
Authors: Antonio Riotto, Martin S Sloth
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2019012622