George tells us what happens in gravitational wave detectors when you quantise the gravitational field.

He talks about a calculation he did with Maulik Parikh and Frank Wilczek which examines what effect quantising the gravitational field would have on gravitational wave detectors.

They first treat the detector and gravitational field quantum mechanically. For certain gravitational wave states (e.g. a coherent state, a squeezed state and a thermal state) they are then able to solve the gravitational field parts of the resulting path integral (or canonical expectation values).

In the resulting expression they then take the most probable path for the detector (i.e. the classical path) and determine an equation of motion for the distance between the ends of the detector (i.e. the classical equation of motion for the detector, with quantum effects from the gravitational field included).

This new equation of motion is like the purely classical one except with the addition of a new noise term. In the case of a squeezed state this noise can be exponentially enhanced, which might have implications for gravitational waves from inflation, which at least start out in a squeezed state.

George: https://www.linkedin.com/in/george-zahariade-844b27b4
Papers: https://arxiv.org/abs/2010.08208 and https://arxiv.org/abs/2010.08205
Essay: https://arxiv.org/abs/2005.07211