If gravity can be thought of as both a wave (the gravitational wave, as predicted to exist by Albert Einstein and certain calculations) and a particle (the graviton), would it make sense to apply quantum mechanics (which I understand only applies to mass/energy) and therefore wavefunction collapse to gravity? In other words, does gravity exhibit wave-particle duality as light does, and thus is it susceptible to wavefunction collapse? If so, what would the implications of the wavefunction collapse of a gravitational wave be?

To better sum up my question: could a gravitational wave be described as a wavefunction?

I would appreciate it if anyone could help me understand if this is a valid concept, or if there are any other theories and concepts that would help me understand gravity and quantum mechanics combined (quantum field theory?).

## Best Answer

At the moment the only candidates for describing a quantized gravitational field and at the same time embed the standard model of particle physics, are string theories . There is no quantization of gravity alone, as following the recipe for quantizing other fields leads to infinities due to the spin 2 of the proposed graviton. Quantisation of gravity is a field of active theoretical physics research.

We have experimental evidence that general relativity holds. We do not have experimental evidence that a graviton exists. We can assume it does and then theorize about interactions of the graviton as wave/particle with other fields and wave functions, but it is just an imaginary exercise at this level.

And yes, you would need as prerequisite quantum field theory to start understanding string theory.

P.S. The

collapseof the wavefunction concept is misleading, as the wave itself is not a wave in the field. It is a probability wave for finding a particle in an (x,y,z,t) location.