Скачать или смотреть Sebastian Cespedes & Sadra Jazayeri | Peeking into Sub-Hubble Scales with Inflationary Phonons

Parallel Talk | Cosmology from Home 2024
https://www.cosmologyfromhome.com/

Talk title: Peeking into Sub-Hubble Scales with Inflationary Phonons
Speaker: Sebastian Cespedes & Sadra Jazayeri

Talk abstract:
Cosmological correlators provide a unique opportunity to probe fundamental physics at energy scales near the Hubble rate during inflation, around 10^14 GeV. Current observations support canonical single-field models by matching existing data on two-point statistics, while also predicting minimal primordial non-Gaussianity. However, upcoming CMB and LSS surveys hold the potential to measure f_{nl} with increased precision, opening avenues to explore new physics during inflation above the Hubble scale. In recent years, there have been many new techniques developed for computing correlation functions at tree level. Nevertheless, little progress has been made so far beyond that. Crucially, some effects start appearing at the one-loop level, highlighting the importance of developing new techniques to compute the signals of these particles. In this presentation, we will focus on the signatures of particles of different spins that interact with scalar fluctuations solely at the quantum level within the EFT of inflation, specifically at one-loop. Utilising spectral decomposition and QFT functional methods, we will demonstrate that when the speed of sound of scalar fluctuations is small, the impact of relativistic heavy fields can be effectively captured by incorporating a series of (spatially) non-local operators into the EFT of single-field inflation. Furthermore, we will illustrate that within this approximation, simple analytical solutions to the one-loop bubble diagrams contributing to the bispectrum and trispectrum can be obtained.