Equation 92 · Part 1 · The Atlas That Refuses to Close
Symbol hat A
What this part means
the weak value of any observable.
Its job in the formula
hat A is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Full expression→Symbol hat A→Article meaning
Where the article explains it
The weak value of any observable , position among them, conditioned on that postselection is = , introduced by Aharonov, Albert, and Vaidman as the quantity a weakly coupled pointer’s mean shift actually reports, to leading order in the coupling strength, once the postselection has been performed [ 11 ] .
The passage around this formula
introduced by Aharonov, Albert, and Vaidman as the quantity a weakly coupled pointer’s mean shift actually reports, to leading order in the coupling strength, once the postselection has been performed [ 11 ] . is not an eigenvalue of , not an expectation value in the ordinary sense, and not guaranteed to be real: it is built from an amplitude ratio over a sub-ensemble selected by an event, the postselection, that has not yet happened at the time the weak coupling acts.
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Sources cited in the surrounding passage
These citations provide research context; check each source for the exact claim it supports.