Can a resonant-mass gravitational-wave detector have wideband sensitivity?

Abstract

In principle, for an impulsive gravitational-wave signal, the signal-to-noise ratio for a resonant-mass antenna is independent of frequency if the limiting noise source is the antenna thermal noise. A gain-bandwidth restriction only arises when the coupling of the resonant antenna to the output amplifier is considered. Applying Bode's gain-bandwidth theorem we are able to derive in a general way the linear amplifier sensitivity limit for a resonant-mass detector. The practical bandwidth limits for a detector utilizing a superconducting inductive transducer are discussed. A fractional bandwidth of ∼0.17 appears feasible with current technology. Additional bandwidth and sensitivity can be achieved with an array of detectors.