1301.4328 (Bengt E Y Svensson)

What is a quantum-mechanical 'weak value' the value of?    [PDF]

Bengt E Y Svensson

A so called 'weak value' of an observable in quantum mechanics (QM) may be obtained in a weak measurement + post-selection procedure on the QM system under study. Applied to number operators, it has been invoked in order to throw light on some QM paradoxes (e.g., the so called Three-Box paradox and Hardy's paradox). This requires the weak value to be interpreted as a bona fide property of the system considered, a par with entities like operator mean values and eigenvalues. I question such an interpretation by showing how, e.g., the freedom in choosing the post-selected state leads to results which it is difficult to make sense of within such a straight-forward interpretation.

View original: http://arxiv.org/abs/1301.4328