Edward Witten – Institute for Advanced Study
Wednesday, December 14, 10:45AM (Zoom meeting starts at 10:30)
"An Observer in De Sitter Space"
In quantum mechanics we usually consider the observer to be external to the system being studied, but in the context of gravity, especially in a closed universe, it may be necessary to explicitly take into account the observer and the observer's gravity. After a general discussion of what an observer can observe, I will describe the example of de Sitter space, where it is necessary to explicitly take into account the gravity of the observer. (This example was analyzed in arXiv:2206.10780 with V. Chandrasekharan, R. Longo, and G. Penington.)