Turning on the Cosmological Collider
Speaker
Date
Time
Place
Cosmology Hall (Room 7W3)
Abstract
With an energy scale up to 10^12 TeV, inflation could involve physical processes far beyond the realm of the standard model. Many fundamental questions about the early Universe remain unanswered: what fields were present? How did they interact with each other? In this seminar, I will demonstrate how modern cosmological datasets can be used to shed light on the early Universe through searches for subtle non-Gaussian correlations induced by particle interactions during inflation, predicted from cosmological collider program. In particular, I will present new searches for inflationary signals in Cosmic Microwave Background and Galaxy Survey data, which allow for a detailed study of the primordial three- and four-point functions and the underlying primordial Lagrangian. Made possible with an array of theoretical and computational tricks, these bound probe particle scattering in the early Universe, providing the highest-energy particle physics known to humankind. I will close by discussing key challenges in cosmological collider searches and future avenues of exploration.
Biography
Oliver Philcox is an Assistant Professor in Physics at Stanford University, affiliated with the Kavli Institute for Particle Astrophysics and Cosmology and the Leinweber Institute for Theoretical Physics. His research spans theoretical, statistical, and observational cosmology, with a particular focus on extracting fundamental physics from galaxy surveys and the cosmic microwave background. He has developed new methods for measuring, modeling, and interpreting cosmological data, with applications to the early universe, inflation, and the large-scale structure of the universe. Together with Mikhail Ivanov and Marko Simonović, he received the 2024 New Horizons Prize in Physics for contributions to the Effective Field Theory of Large Scale Structure.