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Equation 14 · Part 1 · The Corner of the Equivalence Principle No Experiment Has Touched

Symbol hateta_ent

η^ent\hat\eta_{ent}
η^ent\hat\eta_{ent}

What this part means

hatetaea_ent is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

Its job in the formula

hatetaea_ent is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

The passage around this formula

…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 built to see. And η^ent\hat\eta_{ent} is the one component with no single-system analogue at all: it is defined only on a joint state of two systems, and it is nonzero precisely when the expectation value of the joint operator on an entangled state fails to equal the sum of what each system would show alone,…

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