The Juggled interferometer (JIFO) is an earth-based gravitational wave detector using repeatedly free-falling test masses. With no worries of seismic noise and suspension thermal noise, the JIFO can have much better sensitivity at lower frequencies than the current earth-based gravitational wave detectors. The data readout method of a JIFO could be challenging if one adopts the fringe-locking method. We present a phase reconstruction method in this paper by building up a complex function which has a fringe-independent signal-to-noise ratio. Considering the displacement noise budget of the Einstein Telescope (ET), we show that the juggled test masses significantly improve the sensitivity at 0.1-2.5Hz even with discontinuous data. The science cases brought with the improved sensitivity would include detecting quasi-normal modes of black holes with 104−105M⊙, testing Brans-Dicke theory with black-hole and neutron-star inspirals, and detecting primordial-black-hole-related gravitational waves.
@article{arxiv.2207.09214,
title = {Conceptual design and science cases of a juggled interferometer for gravitational wave detection},
author = {Bin Wu and Tomohiro Ishikawa and Shoki Iwaguchi and Ryuma Shimizu and Izumi Watanabe and Yuki Kawasaki and Yuta Michimura and Shuichiro Yokoyama and Seiji Kawamura},
journal= {arXiv preprint arXiv:2207.09214},
year = {2022}
}