Using LIGO-Virgo as a gravitational wave Hanbury Brown--Twiss interferometer.

We propose using the LIGO-Virgo detector network as a Hanbury Brown--Twiss (HBT) interferometer. Our focus is on the behavior of the gravitational waves at the detector rather than the source. We examine HBT interferometry for gravitational waves from binary inspirals which are currently detectable with the LIGO-Virgo network. Previous work on HBT interferometry for gravitational waves has concentrated on characterization of both classical and non-classical properties of signals from cosmological sources in the early Universe which are not detectable by the LIGO-Virgo network. Since the HBT effect can be described equally via classical intensities or via quantum graviton creation/annihilation operators, observation of this effect would not provide an unambiguous demonstration of the quantization of gravity. However, the observation of the HBT effect by LIGO-Virgo would provide a new tool in the detection and analysis of gravitational wave signals.