2013/10/31 by Bjorn Garbrecht, Gerasimos Rigopoulos, Yi Zhu · 1 citation
Physics and Astronomy · #hep-th #gr-qc
paper · pdf · doi:10.1103/physrevd.89.063506
published as Phys. Rev. D 89, 063506 (2014) · 27 pages, minor corrections, references added
arxiv created 2013/11/03 · arxiv updated 2014/03/12
We consider massive λϕ4 theory in de Sitter background. The mass of the scalar field ϕis chosen small enough, such that the amplification of superhorizon momentum modes leads to a significant enhancement of infrared correlations, but large enough such that perturbation theory remains valid. Using the Closed-Time-Path approach, we calculate the infrared corrections to the two-point function of ϕto 2-loop order. To this approximation, we find agreement with the correlation found using stochastic methods. When breaking the results down to individual Feynman diagrams obtained by the two different methods, we observe that these agree as well.