Expectation value of the expectation value

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SUMMARY

The expectation value of the position observable, denoted as = ∫ψ*xψdx, represents a fundamental concept in quantum mechanics. The discussion clarifies that the expectation value of the expectation value, <> = , remains consistent because it reflects the intrinsic nature of averages. Specifically, averaging an average yields the same result, as demonstrated with the numerical example of the set A={2,8}, where the average remains 5 regardless of how many times it is averaged.

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  • Understanding of quantum mechanics principles, particularly expectation values
  • Familiarity with integrals and their application in physics
  • Basic knowledge of wave functions (ψ) in quantum mechanics
  • Concept of averages in mathematics
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Homework Statement


The expectation value of the position observable x is <x> = ∫ψ*xψdx. The expectation value of the expectation value, <<x>>=<x>, is still the expectation value...why?


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The Attempt at a Solution



All I can think of is that the expectation value is essentially an average, and the average of an average is the original average.

i.e.) A={2,8} The average is (2+8)/2 = {5}
The average of {5} = {5}.
 
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The expectation value is a number which <comes out> of the integral of the expectation value of the the expectation value.
 

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