Quantum signatures in nonlinear gravitational waves

Understand

The effective quantum field theory description of gravity, despite its non-renormalizability, allows for predictions beyond classical general relativity.

• As we enter the age of gravitational wave astronomy, an important and timely question is whether measurable quantum predictions that depart from classical gravity, analogous to quantum optics effects which cannot be explained by classical electrodynamics, can be found.
• In this work, we investigate quantum signatures in gravitational waves using tools from quantum optics.
• Squeezed-coherent gravitational waves, which can exhibit sub-Poissonian graviton statistics, can enhance or suppress the signal measured by an interferometer, a characteristic effect of quantum squeezing.