An optoacoustical gravitational antenna

An optoacoustical gravitational detector that structurally combines the principles of interferometric and solid-state gravitational antennas is described. A large acoustical resonator, which is matched to a commensurate Fabry-Perot (FP) optical interferometer, serves as the sensitive element for recording changes in the gravitational-field gradient. In a test experiment, the spectral density of recorded spatial deformations (metric variations) was 10−19 Hz−1/2 at a frequency of ∼1.3 kHz within a band of ∼4 Hz, which can be extended by an order of magnitude upon a corresponding increase in the sharpness of the interferometer mirrors. The new antenna is designed for detecting relativistic catastrophes (collapses) in the Galaxy and the nearest vicinity during complex (multichannel) monitoring with neutrino telescopes of the Baksan Neutrino Observatory of the Institute for Nuclear Research, Russian Academy of Sciences.