2021/07/31 by David Meltzer, David O. Meltzer · 92 citations
Mathematics · Physics and Astronomy · #Analytic continuation #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #De Sitter space #De Sitter universe #Factorization #Galaxies: Formation, Evolution, Phenomena #Homogeneous space #Inflation (cosmology) #Invariant (physics) #Mathematical analysis #Mathematical physics #Mathematics #Physics #Propagator #Quantum mechanics #Scalar (mathematics) #Theoretical physics #Unitarity #Universe #Wave function #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1088/1475-7516/2021/12/018
published in Journal of Cosmology and Astroparticle Physics 2021(12), 018 (Institute of Physics) · 29 pages + appendices, v2: Typos corrected and references added v3: Added comments on Regge limit in the conclusion
arxiv created 2021/11/18 · openalex publication_date 2021/12/01 · arxiv updated 2021/12/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/08
Abstract We study the analytic properties of tree-level wavefunction coefficients in quasi-de Sitter space. We focus on theories which spontaneously break dS boost symmetries and can produce significant non-Gaussianities. The corresponding inflationary correlators are (approximately) scale invariant, but are not invariant under the full conformal group. We derive cutting rules and dispersion formulas for the late-time wavefunction coefficients by using factorization and analyticity properties of the dS bulk-to-bulk propagator. This gives a unitarity method which is valid at tree-level for general n -point functions and for fields of arbitrary mass. Using the cutting rules and dispersion formulas, we are able to compute n -point functions by gluing together lower-point functions. As an application, we study general four-point, scalar exchange diagrams in the EFT of inflation. We show that exchange diagrams constructed from boost-breaking interactions can be written as a finite sum over residues. Finally, we explain how the dS identities used in this work are related by analytic continuation to analogous identities in Anti-de Sitter space.