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Quantum mechanics and the equivalence principle

P. C. W. Davies
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Abstract

A quantum particle moving in a gravitational field may penetrate the classically forbidden region of the gravitational potential. This raises the question of whether the time of flight of a quantum particle in a gravitational field might deviate systematically from that of a classical particle due to tunnelling delay, representing a violation of the weak equivalence principle. I investigate this using a model quantum clock to measure the time of flight of a quantum particle in a uniform gravitational field, and show that a violation of the equivalence principle does not occur when the measurement is made far from the turning point of the classical trajectory. I conclude with some remarks about the strong equivalence principle in quantum mechanics.

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P. C. W. Davies. 2004-03-03. Quantum mechanics and the equivalence principle. https://doi.org/10.1088/0264-9381%2F21%2F11%2F017

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