The separate universe approach to soft limits

2016/05/31 by Zachary Kenton, David J. Mulryne · 1 citation
Economics, Econometrics and Finance · Physics and Astronomy · #Astrophysics #Black Holes and Theoretical Physics #Classical mechanics #Cosmic microwave background #Cosmology and Gravitation Theories #De Sitter universe #Formalism (music) #Inflation (cosmology) #Non-Gaussianity #Physics #Quantum mechanics #Statistical physics #Stochastic processes and financial applications #Theoretical physics #Trispectrum #Universe #astro-ph.CO #gr-qc #hep-th

paper · pdf · doi:10.1088/1475-7516/2016/10/035

28 pages, 7 figures. This is an author-created, un-copyedited version of an article published in JCAP. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at the DOI below. v3: Updated to match version published in JCAP

openalex publication_date 2016/10/21 · arxiv created 2016/12/09 · arxiv updated 2016/12/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We develop a formalism for calculating soft limits of n -point inflationary correlation functions using separate universe techniques. Our method naturally allows for multiple fields and leads to an elegant diagrammatic approach. As an application we focus on the trispectrum produced by inflation with multiple light fields, giving explicit formulae for all possible single- and double-soft limits. We also investigate consistency relations and present an infinite tower of inequalities between soft correlation functions which generalise the Suyama-Yamaguchi inequality.

Citations

• Generating the cosmic microwave background power asymmetry withgNL
• The spectrum of cosmological perturbations produced by a multi-component inflaton to second order in the slow-roll approximation
• Dominance of gauge artifact in the consistency relation for the primordial bispectrum
• Consistency relation for multifield inflation scenario with all loop contributions
• Non-Gaussian features of primordial fluctuations in single field inflationary models
• Conformal symmetries of adiabatic modes in cosmology
• A more accurate analytic calculation of the spectrum of cosmological perturbations produced during inflation
• The importance of slow-roll corrections during multi-field inflation
• On the initial state and consistency relations
• Adiabatic modes in cosmology
• Primordial trispectrum from inflation
• A General Analytic Formula for the Spectral Index of the Density Perturbations produced during Inflation
• Quantum contributions to cosmological correlations
• Cosmological Collider Physics
• Non-Gaussianity Consistency Relation for Multifield Inflation

Cited by

• Numerical evaluation of the bispectrum in multiple field inflation—the transport approach with code