What is the value of an observable between pre- and postselection?
arXiv:quant-ph/0308137 · doi:10.1016/j.physleta.2004.01.041
Abstract
Hall's recent derivation of an exact uncertainty relation [Phys. Rev. A64, 052103 (2001)] is revisited. It is found that the Bayes estimator of an observable between pre- and postselection equals the real part of the weak value. The quadratic loss function equals the expectation of the squared imaginary part of the weak value.
5 pages, accepted in Phys. Lett. A