Is gravitational entanglement evidence for the quantization of spacetime?

Understand

Experiments witnessing the entanglement between two particles interacting only via the gravitational field have been proposed as a test whether gravity must be quantized.

• In the language of quantum information, a non-quantum gravitational force would be modeled by local operations with classical communication (LOCC), which cannot generate entanglement in an initially unentangled state.
• This idea is criticized as too constraining on possible alternatives to quantum gravity.
• We present a parametrized model for the gravitational interaction of quantum matter on a classical spacetime, inspired by the de Broglie-Bohm formulation of quantum mechanics, which results in entanglement and thereby provides an explicit counterexample to the claim that only a quantized gravitational field possesses this capability.