Quantum effects in gravitational wave signals from cuspy superstrings

TL;DR

This paper investigates quantum gravitational wave signals emitted by cuspy superstrings, demonstrating that quantum effects are sharply peaked around classical predictions due to the detector's filtering, with implications for gravitational wave detection.

Contribution

It provides the first quantum analysis of gravitational radiation from cuspy superstrings, linking quantum fluctuations to classical burst signals in gravitational wave observations.

Findings

Quantum signals are sharply peaked around classical predictions.

Detector filtering suppresses high-frequency quantum fluctuations.

Classical burst signals are robust against quantum noise.

Abstract

We study the gravitational emission, in Superstring Theory, from fundamental strings exhibiting cusps. The classical computation of the gravitational radiation signal from cuspy strings features strong bursts in the special null directions associated to the cusps. We perform a quantum computation of the gravitational radiation signal from a cuspy string, as measured in a gravitational wave detector using matched filtering and located in the special null direction associated to the cusp. We study the quantum statistics (expectation value and variance) of the measured filtered signal and find that it is very sharply peaked around the classical prediction. Ultimately, this result follows from the fact that the detector is a low-pass filter which is blind to the violent high-frequency quantum fluctuations of both the string worldsheet, and the incoming gravitational field.