2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/104445We 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.5 pages, no figuresGeneral Relativity and Quantum Cosmologytext