# Cosmological Correlators From Flat Space Feynman Integrals

- Institution: CERN
- Department: TH institutes
- Speaker: Sadra Jazayeri
- Year: 2024
- Language: English
- Subjects: Astronomy and space
- Source: [CERN](https://videos.cern.ch/record/3019555)
- Licence: [CERN](http://copyright.web.cern.ch)
- Who can watch: Tweens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

In this talk, I present a novel connection between cosmological correlators and flat-space Feynman diagrams in momentum space. Focusing on Witten diagrams with heavy internal lines and light external legs, I establish a **Massive Flat Space (MFS) limit**. In this limit, such heavy diagrams simplify to contact graphs with a vertex factor equal to the amputated n-point diagram in flat space. As an application of the MFS limit, I obtain **simple expressions for specific inflationary one-loop graphs, in the small sound speed regime.**.

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## Lectures

1. [Cosmological Correlators From Flat Space Feynman Integrals](https://invisiblenetwork.ai/learn/cern/3019555/8f0ddf0ceab9), 25 min (CERN's player)