(1) Shreya Vardhan: Estimating time in quantum chaotic systems and black holes

Abstract: A time-evolved state in a unitary chaotic quantum many-body system macroscopically resembles a thermal density matrix. However, while a thermal density matrix does not evolve with time, a pure state undergoing unitary evolution must continue to evolve with time unless it is an energy eigenstate. We sharpen this difference by considering an information-theoretic task where we attempt to estimate the time for which the state has been evolved by making measurements on the state. We quantify the effectiveness of the time estimate using a quantity from quantum metrology called the quantum Fisher information (QFI). This quantity shows an interesting interplay between expectations from thermalization and constraints from unitarity. In the context of evaporating black holes, these results imply that the ability to make local time estimates suddenly improves after the Page time. 

(2) Herman Verlinde: Double Scaled SYK Model and de Sitter Holography

(3) Philip Argyres: Light ray operators and lightlike conformal defects