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Expectation values of observables

  • Page ID
    5277
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    Recall the basic formula for the expectation value of an observable \(A\):

    \[\langle A \rangle = {1 \over Q(\beta)}{\rm Tr}(Ae^{-\beta H})\]


    Two important cases pertaining to the evaluation of the trace in the coordinate basis for expectation values will be considered below:

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