English

What is the value of an observable between pre- and postselection?

Quantum Physics 2009-11-10 v2

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.

Cite

@article{arxiv.quant-ph/0308137,
  title  = {What is the value of an observable between pre- and postselection?},
  author = {Lars M. Johansen},
  journal= {arXiv preprint arXiv:quant-ph/0308137},
  year   = {2009}
}

Comments

5 pages, accepted in Phys. Lett. A

R2 v1 2026-07-22T19:40:46.576Z