Unequal time correlators of stochastic scalar fields in de Sitter space
Abstract
The quantum fluctuations of a test scalar field on superhorizon scale in de Sitter spacetime can be described by an effective one-dimensional stochastic theory corresponding to a particular class of nonequilibrium dynamical systems known as the model A. Using the formulation of the latter in terms of a supersymmetric field theory, we compute various unequal-time correlators at large (superhorizon) time separations and compare with existing quantum field theory computation. This includes perturbative calculations, pushed here up to three-loop order, and a nonperturbative expansion at next-to-leading order. Exploiting the supersymmetry of the stochastic theory, we also derive a spectral representation of the field correlators and a fluctuation-dissipation relation for the infrared modes of the scalar field in de Sitter spacetime.
Keywords
Cite
@article{arxiv.1912.05358,
title = {Unequal time correlators of stochastic scalar fields in de Sitter space},
author = {G. Moreau and J. Serreau},
journal= {arXiv preprint arXiv:1912.05358},
year = {2020}
}
Comments
17 pages, 10 figures; typos corrected, references added, minor changes in Sec. 4C, figures updated