# Celestial Holography Initiative

Celestial Holography aims to apply the holographic principle to spacetimes with vanishing cosmological constant. It maps four-dimensional scattering matrix elements to correlators in a two-dimensional conformal field theory living on the night sky. This map possesses a number of surprising features. It emphasizes infinite-dimensional symmetry enhancements, which are typically hidden in infrared factorization theorems for amplitudes; reorganizes collinear limits as conformal field theory operator product expansions, and mixes ultraviolet and infrared behaviour in a manner that will allow us to make general claims about scattering not obvious from perturbation theory.

The Celestial Holography Initiative at Perimeter Institute is a collaborative research hub for scientists working at the forefront of this fast-emerging field.

Watch Sabrina Pasterski’s 2021 talk “Celestial Amplitudes Program Review”

#### Principal Investigator

#### Postdocs

- Yangrui Hu (Brown PhD '22)
- Bin Zhu (Northeastern PhD '22)
- Adam Ball (Harvard PhD '22)
- Sruthi Narayanan (Harvard PhD '23)

Sabrina Pasterski (PhD Harvard University, 2019) is a high energy theorist who joined the Perimeter faculty in 2021 after completing a Postdoctoral Fellowship at the Princeton Center for Theoretical Science. Her research prior to joining PI includes discovering infinite dimensional symmetry enhancements of the S-matrix, a new observable memory effect in gravity, and a framework for generalizing these features of infrared physics to other theories. As the founder and principal investigator of our new Celestial Holography Initiative, she is leading a team of amplitudes, mathematical physics, and quantum gravity researchers in a concerted effort to tackle the problem of uniting our understanding of spacetime with quantum theory by encoding our universe as a hologram.