A lower limit for Newtonian-noise models of the Einstein Telescope

Abstract

The Einstein Telescope (ET) is a proposed third-generation gravitational-wave (GW) underground observatory. It will have greatly increased sensitivity compared to current GW detectors, and it is designed to extend the observation band down to a few Hz. At these frequencies, a major limitation of the ET sensitivity is predicted to be due to gravitational fluctuations produced by the environment, most importantly by the seismic field, which give rise to the so-called Newtonian noise (NN). Accurate models of ET NN are crucial to assess the compatibility of an ET candidate site with the ET sensitivity target also considering a possible reduction of NN by noise cancellation. With NN models becoming increasingly complex as they include details of geology and topography, it is crucial to have tools to make robust assessments of their accuracy. For this purpose, we derive a lower bound on seismic NN spectra, which is weakly dependent on geology and properties of the seismic field. As a first application, we use the lower limit to compare it with NN estimates recently calculated for the Sardinia and Euregio Meuse-Rhine (EMR) candidate sites. We find the utility of the method, which shows an inconsistency with the predictions for the EMR site, which indicates that ET NN models require further improvement.

16 pages, 4 figures, 2 tables

References in corpus (11)

• Advanced Virgo: a 2nd generation interferometric gravitational wave detector
• Advanced LIGO
• GWTC-2: Compact Binary Coalescences Observed by LIGO and Virgo During the First Half of the Third Observing Run
• Science Case for the Einstein Telescope
• Gravitational-wave physics with Cosmic Explorer: limits to low-frequency sensitivity
• Site-selection criteria for the Einstein Telescope
• Machine learning for gravitational-wave detection: surrogate Wiener filtering for the prediction and optimized cancellation of Newtonian noise at Virgo
• Passive Newtonian noise suppression for gravitational-wave observatories based on shaping of the local topography
• Seismic array measurements at Virgo's West End Building for the configuration of a Newtonian-noise cancellation system
• Observation of a potential future sensitivity limitation from ground motion at LIGO Hanford
• Coherence-based approaches for estimating the composition of the seismic wavefield

Cited by in corpus (7)

• Joint Optimization of seismometer arrays for the cancellation of Newtonian noise from seismic body waves in the Einstein Telescope
• Calibration of the strain amplitude recorded with DAS using a strainmeter array
• Predicting the motion of a high-Q pendulum subject to seismic perturbations using machine learning
• The impact of local noise recorded at the ET candidate sites on the signal to noise ratio of CBC gravitational wave signals for the ET triangle configuration
• Atmospheric Newtonian noise modeling for third-generation gravitational wave detectors
• Fighting Newtonian Noise with Gradient-Based Optimization at the Einstein Telescope
• Impact of correlated seismic and correlated Newtonian noise on the Einstein Telescope