Characterizing Earth gravity field fluctuations with the MIGA antenna for future Gravitational Wave detectors

Understand

Fluctuations of the earth's gravity field are a major noise source for ground-based experiments investigating general relativity phenomena such as Gravitational Waves (GWs).

• Mass density variations caused by local seismic or atmospheric perturbations determine spurious differential displacements of the free falling test masses, what is called Gravity Gradient Noise (GGN); it mimics GW effects.
• This GGN is expected to become dominant in the infrasound domain and must be tackled for the future realization of observatories exploring GWs at low frequency.
• GGN will be studied with the MIGA experiment, a demonstrator for low frequency GW detection based on atom interferometry - now in construction at the low noise underground laboratory LSBB in France.