The Precession Caused by Gravitational Waves

TL;DR

This paper demonstrates that gravitational waves induce a measurable precession in gyroscopes, revealing a new memory effect linked to dual symmetries, with potential implications for detecting gravitational wave phenomena.

Contribution

It introduces a novel gravitational gyroscopic precession effect caused by gravitational waves, connecting it to dual asymptotic symmetries and the spin memory effect.

Findings

Precession rate decays as inverse square of distance from source.

Net rotation ('gyroscopic memory') is proportional to gravitational duality generator.

Estimated effect magnitude for LIGO signals is around 10^{-35} arcseconds.

Abstract

We show that gravitational waves cause freely falling gyroscopes to precess relative to fixed distant stars, extending the stationary Lense-Thirring effect. The precession rate decays as the square of the inverse distance to the source, and is proportional to a suitable Noether current for dual asymptotic symmetries at null infinity. Integrating the rate over time yields a net rotation -- a `gyroscopic memory' -- whose angle reproduces the known spin memory effect but also contains an extra contribution due to the generator of gravitational electric-magnetic duality. The angle's order of magnitude for the first LIGO signal is estimated to be $\Phi\sim 10^{-35}$ arcseconds near Earth, but the effect may be substantially larger for supermassive black hole mergers.