Abstract
The general question of defining the expectation value of an operator for a fixed value of another noncommuting observable is considered and explicit expressions are derived. Due to the noncommutivity of operators a unique definition is not possible, and we consider different possible expressions. Special cases which have previously been considered in the literature are shown to be derivable from the methods presented.
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In honor of Ilya Prigogine on the occasion of his 70th birthday.
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Cohen, L., Lee, C. Conditional expectation values in quantum mechanics. Found Phys 17, 561–574 (1987). https://doi.org/10.1007/BF01882787
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DOI: https://doi.org/10.1007/BF01882787