From on-shell amplitude in AdS to cosmological correlators: gluons and gravitons

TL;DR

This paper develops a recursive bootstrap method to compute gluon and graviton amplitudes in (A)dS spacetime, enabling efficient calculation of cosmological correlators with potential applications in understanding the early universe.

Contribution

It introduces a new recursive bootstrap approach for constructing Mellin-momentum amplitudes in (A)dS, providing detailed calculations and insights into the formalism.

Findings

Successfully computed five-point graviton amplitude in (A)dS

Provided detailed methodology and examples for amplitude calculations

Demonstrated how to derive cosmological correlators from amplitudes

Abstract

We recently introduced a recursive bootstrap method for constructing $n$-point gluon and graviton Mellin-momentum amplitudes in (A)dS spacetime. The power of this approach was illustrated by our successful computation of the first five-point graviton amplitude in (A)dS. In this work, we provide further details of these calculations and start with a more in-depth review of the formalism by offering detailed insights into the motivation for defining on-shell amplitudes in AdS, along with various explicit examples. Furthermore, we demonstrate how cosmological correlators can be effortlessly obtained once the amplitude is determined.