Extending Ground-Based Gravitational-Wave Sensitivity to 5 Hz
Abstract
Extending the sensitivity of terrestrial gravitational-wave detectors below 20 Hz is a long-standing challenge, limited by ground motion and inertial sensing noise. In this letter, we demonstrate ultra-high-vacuum compatible inertial isolation and position sensing technologies that achieve active platform stabilization down to 10 mHz. Our laser position sensors reach a sub-pm/ sensitivity above 10 mHz, independent of the input light polarization, representing a 100-fold improvement over the current LIGO position sensors. In addition, our inertial sensors provide at least a factor of 5 improvement in low-frequency sensitivity compared to state-of-the-art commercial seismometers. We integrate these technologies into a LIGO-like interferometer model and predict a low-frequency sensitivity improvement of up to an order of magnitude at 10 Hz, with enhanced linearity and calibration stability. This extension increases the detection horizon for intermediate-mass black hole binaries of mass by a factor of 3. Our results provide the first experimental demonstration of a practical pathway to sub-10 Hz operation of terrestrial gravitational-wave detectors and establish key technologies for next-generation observatories such as Cosmic Explorer and Einstein Telescope.
Cite
@article{arxiv.2602.23531,
title = {Extending Ground-Based Gravitational-Wave Sensitivity to 5 Hz},
author = {Amit Singh Ubhi and Lari Koponen and Jiri Smetana and Yulin Xia and Haixing Miao and Emilia Chick and John Bryant and Geraint Pratten and Teng Zhang and Richard Mittleman and Peter Fritschel and Alan V. Cumming and Giles Hammond and Denis Martynov},
journal= {arXiv preprint arXiv:2602.23531},
year = {2026}
}