Second-order stochastic theory for self-interacting scalar fields in de Sitter spacetime
File(s)
Accepted version
Author(s)
Cable, Archie
Rajantie, Arttu
Type
Journal Article
Abstract
We introduce a second-order stochastic effective theory for light scalar fields in de Sitter spacetime, extending the validity of the stochastic approach beyond the massless limit and demonstrating how it can be used to compute long-distance correlation functions nonperturbatively. The parameters of the second-order stochastic theory are determined from quantum field theory through a perturbative calculation, which is valid if the self-interaction parameter 𝜆 satisfies 𝜆 ≪𝑚²/𝐻², where 𝑚 is the scalar and 𝐻 is the Hubble rate. Therefore, it allows stronger self-interactions than conventional perturbation theory, which is limited to 𝜆 ≪𝑚⁴/𝐻⁴ by infrared divergences. We demonstrate the applicability of the second-order stochastic theory by comparing its results with perturbative quantum field theory and overdamped stochastic calculations, and discuss the prospects of improving its accuracy with a full one-loop calculation of its parameters.
Date Issued
2022-12-26
Date Acceptance
2022-11-30
Citation
Physical Review D: Particles, Fields, Gravitation and Cosmology, 2022, 106 (12)
ISSN
1550-7998
Publisher
American Physical Society
Journal / Book Title
Physical Review D: Particles, Fields, Gravitation and Cosmology
Volume
106
Issue
12
Copyright Statement
© 2022 American Physical Society
Identifier
http://arxiv.org/abs/2209.02545v2
Subjects
Astronomy & Astrophysics
FLATNESS
HORIZON
INFLATIONARY UNIVERSE
Physical Sciences
Physics
Physics, Particles & Fields
QUANTUM
Science & Technology
Publication Status
Published
Article Number
123522
Date Publish Online
2022-12-26