Introduction to quantum Fisher information
- Dénes Petz (Budapest University of Technology and Economics, Budapest, Hungary)
The subject is a mathematical transition from the Fisher information of classical statistics to the matrix formalism of quantum theory. If the monotonicity is the main requirement, then there are several quantum versions parametrized by a function. In physical applications the minimal is the most popular. There is a one-to-one correspondence between Fisher informations and abstract covariances. The skew information is treated here as a particular case.