Speaker: Prof. Tadashi Takayanagi (Yukawa Institute)

Date and time: Feb. 20 (Tue.), 16:00-

Style: zoom

Title:Aspects of pseudo entropy

Abstract:

Entanglement entropy is a quantum information theoretic quantity which measures the amount of quantum entanglement in a given pure state. Pseudo entropy is a generalization of entanglement entropy such that it depends on both an initial state and final state aiming at a post-selection process. This new quantity was originally motivated by its geometric calculation in the context of holography or AdS/CFT correspondence. The entanglement entropy in conformal field theories can be computed as the area of a minimal surface in a hyperbolic space. The pseudo entropy follows a similar geometric formula in a deformed hyperbolic space (i.e. Euclidean time dependent AdS). At the same time, studies of pseudo entropy in quantum many-body systems have implied that pseudo entropy may serve as a new quantum order parameter. In this talk we would like to review these aspects of pseudo entropy, including its basic definition, motivations, properties and applications.