Hamburg 2001 – wissenschaftliches Programm
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DY: Dynamik und Statistische Physik
DY 14: Brownsche Bewegung
DY 14.6: Vortrag
Montag, 26. März 2001, 15:45–16:00, S 5.5
A simple model for 1/fα noise — •Jörn Davidsen and Heinz Georg Schuster — Institut für Theoretische Physik und Astrophysik, Christian-Albrechts-Universität, Olshausenstraße 40, 24118 Kiel
We present a simple stochastic mechanism which generates pulse trains exhibiting a power law distribution of the pulse intervals and a 1/fα power spectrum over several decades at low frequencies with α close to one. The essential ingredient of our model is a fluctuating threshold which performs a Brownian motion. Whenever an increasing potential V(t) hits the threshold, V(t) is reset to the origin and a pulse is emitted. We show that if V(t) increases linearly in time the pulse intervals can be approximated by a random walk with multiplicative noise. Our model agrees with recent experiments in neurobiology and explains the high interspike interval variability and the occurence of 1/fα noise observed in cortical neurons.