Abstract

Phenomenon of Prebifurcation Noise Enhancement: Linear and Nonlinear Analysis

E.D.Surovyatkina, C.G.Bilchinskaya, I.A.Rychka (State Technical University of Kamchatka, Petropavlovsk-Kamchatsky, Russia); O.Ya.Butkovsky (Vladimir State University, Vladimir, Russia); A.O.Rozanov (GeoForschungsZentrum, Potsdam, Germany); Yu.A.Kravtsov (Space Research Institute RAS, Moscow, Russia)

e-mail: elena@marine.kamchatka.su

The phenomenon of prebifurcation noise enhancement in nonlinear systems with the period doubling bifurcation is studied. Though analysis is performed for discrete systems (quadratic map, multimodal map), many revealed regularities are of general importance. Intensity of fluctuations is estimated both for linear regime (far from bifurcation threshold) and for nonlinear regime (in the vicinity of bifurcation threshold). It is shown that the intensity of driven fluctuations in strongly nonlinear regime, that is directly in a bifurcation point, is proportional to the square root of the external noise intensity, opposite to linear regime, where intensity of fluctuations is proportional to the intensity of external noise. It is pointed out that there is an opportunity to measure the intensity of noise sources in various nonlinear physical systems using data on the prebifurcation noise enhancement. Obtained estimates may be used for analysis of acoustic emission (AE) energy rise close to the point of transition to a new stage of fracturing.

Section : 8