deci-Hz Gravitational Wave Observations on the Moon and Beyond
Emanuele Berti, Marica Branchesi, Alessandra Buonanno, Alessandra Corsi, Daniel J. D'Orazio, Jan Harms, Jason M. Hogan, Francesco Iacovelli, Karan Jani, Marc Kamionkowski, Kentaro Komori, Konstantinos Kritos, Andrea Maselli, M. Coleman Miller, Chiara M. F. Mingarelli, Volker Quetschke, B. S. Sathyaprakash, David H. Shoemaker, Joseph Silk, Jacob P. Slutsky, James Ira Thorpe, James Trippe, Daniele Vetrugno, Stefano Vitale
TL;DR
The deci-Hz GW workshop highlights a rich science case at frequencies between LISA and terrestrial detectors, spanning IMBHs, WD mergers, and primordial backgrounds. It surveys Moon-based (LGWA/LILA), space-based (DECIGO, GW-Space 2050), and atom-interferometry (MAGIS) approaches, stressing that Moon and cislunar platforms could overcome terrestrial Newtonian-noise limits and enable long, pre-merger multi-messenger observations. The discussions emphasize multi-band synergy with LISA and 3G ground-based detectors to sharpen tests of general relativity, map black-hole spacetimes, and perform cosmography with dark sirens, while foreground subtraction remains a central challenge for primordial backgrounds. A parallel GW-Moon 2050 study is urged to chart a timely, technically feasible path that complements free-flyer missions and leverages potential lunar infrastructure and geophysical synergies. The workshop also points to pathfinder efforts like Soundcheck as critical for maturing technologies before committing to full-scale deci-Hz observatories.
Abstract
This document summarizes talks and discussions from the workshop "deci-Hz Gravitational Wave Observations on the Moon and Beyond" that took place at Johns Hopkins University between September 1 and September 3, 2025. The workshop focused on experimental proposals to observe gravitational waves in the deci-Hz band, including lunar detectors, laser interferometers in space, and atom interferometry; gravitational wave sources in the deci-Hz frequency band; and the multi-messenger and multi-band astronomy that would be enabled by these observations.