Eur. Phys. J. Plus (2021) 136: 349
https://doi.org/10.1140/epjp/s13360-021-01362-7

Regular Article

On the measurement of the speed of gravitational waves

¹ Department of Physics and Astronomy, Sun Yat-Sen University, 519082, Zhuhai, China
² School of Physics, Peking University, 100871, Beijing, China

^a dushuang@pku.edu.cn

Received: 25 January 2021
Accepted: 24 March 2021
Published online: 1 April 2021

Abstract

The accurate measurement of the speed of gravitational waves (GWs) is very important for fundamental physics. In this paper, by taking cosmological effect into consideration, we derive a new formula to calculate the speed of GWs on the basis of GW 170817-like events. We find that in the case of high redshift, the luminosity distance used in the previous calculation of the speed of GWs needs to be replaced by co-moving distance. We consider some possible electromagnetic counterparts of gravitational-wave events which can significantly reduce the intrinsic uncertainty between the emission times of the gravitational and electromagnetic signals. Optimistically, the measurement accuracy will be improved to $\sim {10}^{-18}$ m  s${}^{-1}$.