RESONANT GRAVITATIONAL-WAVE ANTENNAS FOR STOCHASTIC BACKGROUND MEASUREMENTS

The sensitivity of a resonant gravitational wave (GW) antenna is calcu lated in terms of spectral density and frequency bandwidth. For a quan tum-limited detector the bandwidth might reach values greater than 100 Hz, with a sensitivity to bursts of h = 3 x 10(-21) (SNR = 1). The sp ectral amplitude sensitivity for the Nautilus detector has been measur ed to be 7 x 10(-22) Hz(-1/2) and its target value is 7 x 10(-23) Hz(- 1/2). Using two near-Nautilus detectors the GW stochastic background c an be measured with a sensitivity, with respect to the critical densit y, of a few 10(-5) for an integration time of one year, as shown by si mulations.