Berlin 2015 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 25: Brownian Motion and Transport (jointly with DY, CPP)

TT 25.3: Vortrag

Montag, 16. März 2015, 15:45–16:00, BH-N 243

Velocity fluctuations of Brownian particle in inhomogeneous media and driven by colored noise as a sourse of 1/f fluctuations — •Rytis Kazakevicius and Julius Ruseckas — Institute of Theoretical Physics and Astronomy, Vilnius University, A. Gostauto 12, LT-01108 Vilnius, Lithuania

Nonlinear stochastic differential equations generating signals with 1/f spectrum in a broad range of frequencies have been used so far to describe socio-economical systems [1]. We have derived such equation from Langevin equations that describe the motion of a Brownian particle in an inhomogeneous environment. The inhomogeneous environment can be a result of a linear potential affecting the Brownian particle together with the steady state heat transfer due to the difference of temperatures at the ends of the medium. The correlation of collisions between the Brownian particle and the surrounding molecules can lead to the situation where the finite correlation time becomes important, thus we have investigated the effect of colored noise in our model. Existence of colored noise leads to the additional restriction of the diffusion and exponential cut-off of the distribution of particle positions. Narrower power law part in the distribution of the particle positions results in the narrower range of frequencies where the spectrum has power law behavior.

[1] V. Gontis, J. Ruseckas and A. Kononovicius, Physica A, 389 100 (2010).