Off-Line Subtraction of Seismic Newtonian Noise

Abstract

A fundamental limit for the sensitivity of an InterferometricGravitational Wave detector in the low frequency region is imposed bythe effect of environmental mass density fluctuations. Thesefluctuations generate stochastic gravitational fields which coupledirectly to the apparatus test masses, bypassing seismic isolationsystems. In this paper the results of a preliminary investigation on thepossibility of reducing this kind of noise are reported. We focus on thefeasibility of off-line noise subtraction. In this approach the massdensity fluctuations are monitored by an appropriate set of measurementdevices. The resulting signals are combined linearly with the output ofthe interferometer to obtain partial cancellation of the noise.