Seismic Background Limitation of Lunar Gravitational-wave Detectors

TL;DR

This paper evaluates the limitations imposed by lunar seismic background on proposed lunar gravitational-wave detectors, analyzing their response to GWs and discussing mitigation strategies to determine their effective observation bands.

Contribution

It provides a comparative analysis of lunar GW detector concepts, highlighting seismic background effects and identifying optimal observation frequencies.

Findings

Lunar seismic noise limits detector sensitivity at certain frequencies.

Different detector designs respond uniquely to lunar seismic activity.

Mitigation strategies can improve the effective observation band.

Abstract

New concepts were recently proposed for gravitational-wave (GW) detectors on the Moon. These include laser-interferometric detectors, proposed as free-range or optical-fiber interferometers, and inertial acceleration sensors. Some of them exploit the response of the Moon to GWs, others follow the design of current laser-interferometric GW detectors, which directly measure the gravitational strain with suspended optics. All of these ideas emerged since the Moon offers an extremely quiet geophysical environment compared to Earth, but at the same time, one must realize that even the quiet lunar environment sets limits to the sensitivity of lunar GW detectors. In this article, we compare the proposed mission concepts in terms of their response to GWs and evaluate how they are affected by the lunar seismic background. We discuss available mitigation strategies. From these analyses, we infer the prime observation band of each detector concept.