A Mellin space approach to cosmological correlators

A Mellin space approach to cosmological correlators

Blog Article

Abstract We propose a Mellin space approach to the evaluation of late-time momentum-space correlation functions of quantum fields in (d + 1)-dimensional de Sitter space.The Mellin-Barnes representation makes manifest the analytic structure of late-time correlators and, more generally, provides a convenient general Leather Hole Punch d framework for the study of conformal correlators in momentum space.In this work we focus on tree-level correlation functions of general scalars as a prototype, including n-point contact diagrams and 4-point exchanges.For generic scalars, both the contact and exchange diagrams are given by (generalised) Hypergeometric functions, which reduce to existing expressions available in the literature for d = 3 and external scalars which are either simultaneously conformally coupled or massless.

This approach can also be used for Baby Teether the perturbative bulk evaluation of momentum space boundary correlators in (d + 1)-dimensional anti-de Sitter space (Witten diagrams).