Is graviton shot noise detectable?

TL;DR

This paper proposes detecting the absence of graviton shot noise in gravitational wave data as a novel way to explore the quantum nature of gravity, suggesting that its presence or absence can reveal fundamental properties of gravitational interactions.

Contribution

It introduces a new method for probing quantum gravity by analyzing graviton shot noise levels in gravitational wave observations, which has not been previously considered.

Findings

Graviton shot noise could be detectable in gravitational wave data.

Absence of graviton shot noise would imply gravity is not a conventional quantum field.

The calculations align with existing literature on graviton detection limits.

Abstract

Direct detection of gravitons in gravitational experiments, including gravitational wave observatories, has been all but ruled out given the weak coupling between the gravitational field and matter. Here we propose an alternative: looking not for the presence but for the absence of graviton shot noise in gravitational wave data. Gravitational wave experiments detect very weak signals that correspond to a surprisingly small number of gravitons even at the relatively low frequencies that characterize signals from gravitational wave events. A detailed calculation, which also yields results that are consistent with the existing literature, demonstrates that graviton shot noise may be present at detectable levels in gravitational wave observations. The absence of elevated noise levels due to graviton shot noise, in turn, would indicate that gravity is not a quantum field theory with a conventional perturbative expansion at low energies.