Abstract:
I am planning to give a compact review of the main results
in the theory and applications of uncertainty relations, accumulated during
98 years after Heisenberg's famous paper of 1927. The main emphasis will be
made on the evolution of the concept of "uncertainty" and various families of
exact inequalities derived for almost a century (especially those that are not
discussed in standard text books on quantum mechanics).
In particular, I pretend to discuss in the historical manner various attempts
to understand how an additional information on a quantum system (e.g.,
the correlation coefficients, quantum purity, quantum entropy, temperature, etc.)
influences the functions characterizing "quantum uncertainties".
The main illustrations will be as follows.
1) Variance inequalities for N arbitrary operators, their generalizations
and the most important special cases.
2) Entropic uncertainty relations and their applications.
3) Uncertainty relations for mixed states (thermal states as a simple example):
the role of "quantum purity" and the Wigner-Yanase "skew information".
4) “Local” uncertainty relations.
5) Applications of the uncertainty relations: Minimal energy of quantum systems,
restrictions on the parameters of master equations, entanglement criteria.
6) Time-energy uncertainty relations; Decay laws and decay times of unstable systems;
Speed of quantum evolution; Arrival and tunneling times.
7) Measurement uncertainty relations.