Derivation of STAT FUNC
The result is proved for a pure state and a non-degenerate discrete
observable A with eigenvalues ai.
We first rewrite the statistical algorithm for projection
operators:
(1) |
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For an arbitrary function f: R
R (where R is the set of real
numbers) we define the function of an observable A as:
Moreover, we introduce the characteristic function
of a number a as:
As a result, we can rewrite a project operator
as:
(2) |
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and thus the statistical algorithm as:
We also use a simple mathematical property of characteristic
functions:
whence we can also write:
(3) |
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Then:
Hence:
Now since
which is STAT FUNC.
Return to The Kochen-Specker Theorem