The Cosmological Bootstrap: Inflationary Correlators from Symmetries, Locality and Unitarity

Abstract

Cosmological correlators are the fundamental observables of early universe cosmology. They are measured in the CMB and the distribution of galaxies and contain the secrets of the first moments of the universe. They share many similarities to flat-space scattering amplitudes but are far more difficult to compute in practice due to the time-dependence of cosmological backgrounds. In this talk, the speaker will introduce the cosmological bootstrap which aims to compute these cosmological observables in more efficient ways compared to the traditional in-in formalism. He will discuss how symmetries, locality and unitarity constrain the structure of cosmological correlators and show how their form can be completely fixed by these physical principles without having to consider the complicated time evolution. He will illustrate these methods in the context of inflationary bispectra and the trispectrum of pure gravity in de Sitter space.

About the Speaker

Dr. David STEFANSZYN completed his PhD at The University of Nottingham in 2016 under the supervision of Antonio PADILLA. Then he held postdoctoral positions at the University of Groningen in The Netherlands and at DAMTP at the University of Cambridge. Dr. Stefanszyn is now back at the University of Nottingham as a senior research fellow and holds a Stephen Hawking fellowship and Nottingham research fellowship.

About the Program

For more information, please refer to the program website at http://iasprogram.ust.hk/particle_theory.

For Attendees' Attention

• Seating is on a first come, first served basis.