Lensing of Gravitational Waves as a Novel Probe of Graviton Mass

Abstract

The diffraction patterns of lensed gravitational waves encode information about their propagation speeds. If gravitons have mass, the dispersion relation and speed of gravitational waves will be affected in a frequency-dependent manner, which would leave potentially detectable traces in the diffraction pattern if the waves are lensed. In this paper, we study how the alternative dispersion relation induced by massive gravitons affects gravitational waves lensed by point-mass lenses, such as intermediate-mass black holes. By detecting a single lensed gravitational-wave signal, we can measure the graviton mass with an accuracy better than the combined measurement across O(10 2 ) unlensed signals. Our method can be generalised to other lens types, gravitational-wave sources, and detector networks, opening up new ways to measure the graviton mass through gravitational-wave detection.

Lensing Magnification Seen by Gravitational Wave Detectors

“…The effects of gravitational lensing on the apparent properties of detected sources and the possible identification of unique lensing features were extensively studied [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]. The prospects of the lensing of gravitational waves alone or in combination with other data as a probe of dark matter or of general relativity have also been investigated [29][30][31][32].…”