The subtle simplicity of cosmological correlators

Chowdhury, Chandramouli; Lipstein, Arthur; Mei, Jiajie; Sachs, Ivo; Vanhove, Pierre

Abstract

We investigate cosmological correlators for conformally coupled ϕ4 theory in four-dimensional de Sitter space. These in-in correlators differ from scattering amplitudes for massless particles in flat space due to the spacelike structure of future infinity in de Sitter. They also require a regularization which preserves de Sitter-invariance, which makes the flat space limit subtle to define at loop-level. Nevertheless we find that up to two loops, the in-in correlators are structurally simpler than the wave function and have the same transcendentality as flat space amplitudes. Moreover, we show that their loop integrands can be recast in terms of flat space integrands and can be derived from a novel recursion relation.

Citation

Chowdhury, C., Lipstein, A., Mei, J., Sachs, I., & Vanhove, P. (2025). The subtle simplicity of cosmological correlators. Journal of High Energy Physics, 2025(3), Article 7. https://doi.org/10.1007/jhep03%282025%29007

• Journal Article Type: Article
• Acceptance Date: Feb 9, 2025
• Online Publication Date: Mar 4, 2025
• Publication Date: 2025
• Deposit Date: Mar 6, 2025
• Publicly Available Date: Mar 6, 2025
• Journal: Journal of High Energy Physics
• Print ISSN: 1126-6708
• Electronic ISSN: 1029-8479
• Publisher: Scuola Internazionale Superiore di Studi Avanzati (SISSA)
• Peer Reviewed: Peer Reviewed
• Volume: 2025
• Issue: 3
• Article Number: 7
• DOI: https://doi.org/10.1007/jhep03%282025%29007
• Keywords: Scattering Amplitudes, AdS-CFT Correspondence
• Public URL: https://durham-repository.worktribe.com/output/3680768