Mathematical analysis

Inflation (cosmology)

De Sitter space

Scalar (mathematics)

Universe

Propagator

Geometry

Physics

De Sitter universe

Mathematics

Mathematical physics

Theoretical physics

Quantum mechanics

Homogeneous space

Unitarity

Analytic continuation

Invariant (physics)

Algorithm

Wave function

Factorization

Journal of Cosmology and Astroparticle Physics

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.

The inflationary wavefunction from analyticity and factorization