Events Daily

Thursday, December 2, 2021

The Cosmological Horizon, Macrostates, and Microstates
Eva Silverstein, Stanford University
Event Type: Physics Dept Colloquium
Time: 4:00 PM -
Location: 726 Broadway, 940, CCPP Seminar
Abstract: The cosmological horizon plays a key role in cosmology. In the early universe, it creates perturbations seeding structure starting from super-horizon modes created during inflation. Current and future observational data contains a wealth of information about this nearly-Gaussian state of the macroscopic field modes (with many interesting challenges involved in extracting it). The horizon also plays a central role in thought experiments going back to work of Gibbons and Hawking. Their calculations indicated an emergent picture of spacetime in which the horizon area in units of the Newton constant corresponds to an entropy, suggesting a corresponding count of microstates. Combining several disparate developments in theoretical physics to be introduced in the talk, we will present recent results reproducing this microstate count along with the emergent de Sitter geometry in a tractable model, raising many new questions for further research.