Detection of Weak Gravitational Waves by Interferometric Methods and Problem of Invertible Calculations

The fundamental features of the detection of non-stationary undulatory perturbations of metrics based on the interference effects are considered. The advantage of the Aharonov-Bohm effect in superconductors for these purposes in comparison with the ordinary optical interference is demonstrated. Some circuitries of the interferometric detectors in order to be used with SQUID are suggested. The possibilities of lowering the noise temperature of the ultraweak signals detectors based on the analogy between the processes of high-sensitive measurements and the reversible calculations are discussed. The question about the detectability and the possibility of principle to carry out in practice the recording of gravitational waves (GW) had been brought up for the first time in the works of Bondi [1] and Weber [2]. The Bondi’s mental experiment (friction of the beads that are “pushed away by the perturbation of metric” under the action of GW, a prototype of the modern laserinterferometric detectors [3, 4]), as well as the Weber’s real experiments [5] with the massive aluminum antenna, equipped with piezo-sensors, have implied an energy transfer of GW to the mechanical system. Before these authors represented their own statements, it has been proposed a recording method of GW [6], assuming the conversion of the wave energy into the elastic-strain energy of a body with magnetostrictive properties (fig. 1). The possibility of recording a magnetic response, caused by the deformation of a magnetostrictive sample, of the superconductive quantum interferometer (SQUID) has brought the high efficiency to the method. On the present-day sensitivity the SQUID’s are capable to register 10−7Φ0 Hz −1/2, where Φ0 ≃ 2.07×10−15 Wb is the flux quantum. The basic estimations on the basis of the actual parameters of magnetostrictive materials have allowed us to think of the possibility of enhancing the sensitivity of the proposed method in terms of GW metric tensor oscillation amplitude to the level of | δgij | ≃ 2.5×10−23 Hz−1/2.