Skip to main content

Research Repository

Advanced Search

On graviton non-Gaussianities in the Effective Field Theory of Inflation

Cabass, Giovanni; Stefanyszyn, David; Supeł, Jakub; Thavanesan, Ayngaran

On graviton non-Gaussianities in the Effective Field Theory of Inflation Thumbnail


Giovanni Cabass

Jakub Supeł

Ayngaran Thavanesan


We derive parity-even graviton bispectra in the Effective Field Theory of Inflation (EFToI) to all orders in derivatives. Working in perturbation theory, we construct all cubic interactions that can contribute to tree-level graviton bispectra, showing that they all come from EFToI operators containing two or three powers of the extrinsic curvature and its covariant derivatives: all other operators can be removed by field redefinitions or start at higher-order in perturbations. For operators cubic in the extrinsic curvature, where the single-clock consistency relations are satisfied without a correction to the graviton two-point function, we use the Manifestly Local Test (MLT) to efficiently extract the effects of evolving graviton fluctuations to the end of inflation. Despite the somewhat complicated nature of the bulk interactions, the final boundary correlators take a very compact form. For operators quadratic in the extrinsic curvature, the leading order bispectra are a sum of contact and single exchange diagrams, which are tied together by spatial diffeomorphisms, and to all orders in derivatives we derive these bispectra by computing the necessary bulk time integrals. For single exchange diagrams we exploit factorisation properties of the bulk-bulk propagator for massless gravitons and write the result as a finite sum over residues. Perhaps surprisingly, we show these single exchange contributions have only total-energy poles and also satisfy the MLT.


Cabass, G., Stefanyszyn, D., Supeł, J., & Thavanesan, A. (2022). On graviton non-Gaussianities in the Effective Field Theory of Inflation. Journal of High Energy Physics, 2022(10), Article 154.

Journal Article Type Article
Acceptance Date Oct 12, 2022
Online Publication Date Oct 24, 2022
Publication Date Oct 1, 2022
Deposit Date Nov 7, 2022
Publicly Available Date Nov 10, 2022
Journal Journal of High Energy Physics
Electronic ISSN 1029-8479
Peer Reviewed Peer Reviewed
Volume 2022
Issue 10
Article Number 154
Keywords Regular Article - Theoretical Physics, Effective Field Theories, Space-Time Symmetries, Early Universe Particle Physics
Public URL
Publisher URL


You might also like

Downloadable Citations