ON ENTROPIES OF QUANTUM DYNAMICAL SYSTEMS

摘要

Classical dynamical entropy is an important tool to discuss coding theorems in classical information theory. Quantum dynamical entropy was first studied by Connes, Stormer and Emch. Thereafter, there have been many researches to construct or calculate the dynamical entropies for several models. In this paper, we briefly review two formulations due to (i) Ohya and (ii) Kossakowski, Ohya and Watanabe. Some numerical computations of these entropies are carried for several states.