We argue that if the Newtonian gravitational field of a body can mediate
    entanglement with another body, then it should also be possible for the body
    producing the Newtonian field to entangle directly with on-shell gravitons. Our
    arguments are made by revisiting a gedankenexperiment previously analyzed by
    Belenchia et al., which showed that a quantum superposition of a massive body
    requires both quantized gravitational radiation and local vacuum fluctuations
    of the spacetime metric in order to avoid contradictions with complementarity
    and causality. We provide a precise and rigorous description of the
    entanglement and decoherence effects occurring in this gedankenexperiment,
    thereby significantly improving upon the back-of-the-envelope estimates given
    in the analysis of Belenchia et al. and also showing that their conclusions are
    valid in much more general circumstances. As a by-product of our analysis, we
    show that under the protocols of the gedankenexperiment, there is no clear
    distinction between entanglement mediated by the Newtonian gravitational field
    of a body and entanglement mediated by on-shell gravitons emitted by the body.
    This suggests that Newtonian entanglement implies the existence of graviton
    entanglement and supports the view that the experimental discovery of Newtonian
    entanglement may be viewed as implying the existence of the graviton.

    Source link


    Leave A Reply