The gravitational coupling of nearby massive bodies to test masses in a gravitational wave (GW) detector cannot be shielded, and gives rise to 'gravity gradient noise' (GGN) in the detector. In this paper we show that for any GW detector using local test masses in the Inner Solar System, the GGN from the motion of the field of $\sim 10^5$ Inner Solar System asteroids presents an irreducible noise floor for the detection of GW that rises exponentially at low frequencies. This severely limits prospects for GW detection using local test masses for frequencies $f_{\text{GW}} \lesssim (\text{few})\times 10^{-7}\,$Hz. At higher frequencies, we find that the asteroid GGN falls rapidly enough that detection may be possible; however, the incompleteness of existing asteroid catalogs with regard to small bodies makes this an open question around $f_{\text{GW}}\sim μ$Hz, and further study is warranted. We show that a detector network placed in the Outer Solar System would not be overwhelmed by this noise above $\sim 10\,$nHz, and make comments on alternative approaches that could overcome the limitations of local test masses for GW detection in the $\sim 10\,$nHz-$μ$Hz band.
Prospects for Observing Gravity-gradient Noise and Earthquake Gravity Signals with CHRONOS
National Institute of Physics, University of the Philippines - Diliman（菲律宾大学迪里曼分校国家物理研究所）；Center for High Energy and High Field (CHiP), National Central University（国立中央大学高能高场中心）；Institute of Physics, Academia Sinica（中央研究院物理研究所）；Institute of Particle and Nuclear Studies, High Energy Acceleration Research Organization (KEK)（高能加速器研究机构粒子与核研究部）
Emergent Gravity from Topological Quantum Field Theory: Stochastic Gradient Flow Perspective away from the Quantum Gravity Problem
Anqing Normal University（安庆师范大学）；Laboratori Nazionali di Frascati INFN（INFN弗拉斯卡蒂国家实验室）；Università di Napoli “Federico II”（那不勒斯费德里科二世大学）；Scuola Superiore Meridionale（南方高等学院）；INFN Sezione di Napoli（INFN那不勒斯分部）；Research Center of Astrophysics and Cosmology, Khazar University（Khazar大学天体物理学与宇宙学研究中心）；Tsung-Dao Lee Institute（李政道研究所）；Shanghai Jiao Tong University（上海交通大学）；Fudan University（复旦大学）
