Radio Wave 'Messengers' of Periodic Gravitational Radiation and the   Problem of Gravitationally Induced Nonlinearity in Electrodynamic Systems
  We discuss a gravitationally induced nonlinearity in hierarchic systems. We consider the generation of extremely low-frequency radio waves with a frequency of the periodic gravitational radiation; the generation is due to an induced nonlinear self-action of electromagnetic radiation in the vicinity of the gravitational-radiation source. These radio waves are a fundamentally new type of response of an electrodynamic system to gravitational radiation. That is why we here use an unconventional term: radio-wave messengers of periodic gravitational radiation. 
A.B. Balakin, Z.G. Murzakhanov (Kazan State U.), G.V. Kisun'ko   (Moscow, Creative Problems Dept.)