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DY: Dynamik und Statistische Physik

DY 46: Poster

DY 46.61: Poster

Donnerstag, 27. März 2003, 15:30–18:00, P1

Self-organization to critical percolation on a random directed network — •Christel Kamp¹ and Stefan Bornholdt² — ¹Institut für Theoretische Physik, Universität Kiel, Germany — ²Interdisziplinäres Zentrum für Bioinformatik, Universität Leipzig, Germany

Self-organization of a directed regulatory network is studied in the presence of percolating activity [1]. Nodes in the network are either active or inactive, while activity propagates from active sites through activating or inhibiting directed links. The system shows a transition from a subcritical regime to a regime with systemwide percolation of activity in dependence on the fraction of randomly chosen activating links in the system. Allowing local adjustments of the network’s links’ characteristics on a slower timescale, may generate self-organized percolation. Here, we consider the rule that a node that shows above (below) average activity compared to its neighbors will eventually obtain an inhibiting (activiating) inlink. As a result, marginal damage spreading occurs in the system which corresponds to self-organization to the percolation transition with a scale-free size distribution of activity avalanches.

[1] C. Kamp, S. Bornholdt, cond-mat/0210410 (2002)