Snippets of Physics: 22. Wigner's function and semi-classical limit

Abstract

Obtaining the classical limit of quantum mechanics turns out to be conceptually and operationally non-trivial and, even today, some of the experts consider this issue to be unsettled. There is a function, originally devised by Wigner, which plays a key role in this aspect and throws some light on the way the cla ssical world emerges from the quantum description.