The measurement of the Hubble constant H0 plays an important role in the study of cosmology. In this letter, we propose a new method to constrain the Hubble constant using the strongly lensed gravitational wave (GW) signals. By reparameterizing the waveform, we find that the lensed waveform is sensitive to the H0. Assuming the scenario that no electromagnetic counterpart of the GW source can be identified, our method can still give meaningful constraints on the H0 with the information of the lens redshift. We then apply Fisher information matrix and Markov Chain Monte Carlo to evaluate the potential of this method. For the space-based GW detector, TianQin, the H0 can be constrained within a relative error of ∼ 0.3-2\%, using a single strongly lensed GW event. Precision varies according to different levels of electromagnetic information.
@article{arxiv.2304.10435,
title = {Measuring the Hubble Constant Using Strongly Lensed Gravitational Wave Signals},
author = {Shun-Jia Huang and Yi-Ming Hu and Xian Chen and Jian-dong Zhang and En-Kun Li and Zucheng Gao and Xin-Yi Lin},
journal= {arXiv preprint arXiv:2304.10435},
year = {2023}
}