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Equation 7 · Part 5 · The Corner of the Equivalence Principle No Experiment Has Touched

Symbol hateta_sup

η^=ηcl+η^diag+η^coh+η^sup+η^ent\hat\eta = \eta_{cl} + \hat\eta_{diag} + \hat\eta_{coh} + \hat\eta_{sup} + \hat\eta_{ent}
η^sup\hat\eta_{sup}

What this part means

hatetasa_sup is one of the signed contributions combined to compute the quantity on the left.

Its job in the formula

hatetasa_sup is one of the signed contributions combined to compute the quantity on the left.

The passage around this formula

…states to free fall, so it only shows up in an experiment that keeps a system in superposition of two internal states long enough for gravity to act on the superposition itself, rather than on each state separately. η^sup\hat\eta_{sup} depends on the system’s external, spatial quantum state beyond the leading order any classical trajectory would need, the component that a spatial superposition test — an atom interferometer’s two arms treated as a single quantum object rather than two separate classical paths — is…

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Learn the underlying idea

A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.

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Sources cited in the surrounding passage

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