Asymptotically Optimal Quantum Universal Quickest Change Detection
It provides the first asymptotically optimal solution for universal quantum change detection, addressing a fundamental problem in quantum information theory.
This paper solves the universal quickest change detection problem for quantum states, where the post-change state is unknown, and proves asymptotic optimality of a two-stage approach in terms of worst-case average detection delay.
This paper investigates the quickest change detection of quantum states in a universal setting: specifically, where the post-change quantum state is not known a priori. We establish the asymptotic optimality of a two-stage approach in terms of worst average delay to detection. The first stage employs block POVMs with classical outputs that preserve quantum relative entropy to arbitrary precision. The second stage leverages a recently proposed windowed-CUSUM algorithm that is known to be asymptotically optimal for quickest change detection with an unknown post-change distribution in the classical setting.