Berlin 2008 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 29: Poster II

DY 29.31: Poster

Thursday, February 28, 2008, 16:00–18:00, Poster C

Self-organization of heterogeneous topology and symmetry breaking in networks with adapative thresholds and rewiring — •Thimo Rohlf — Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA

We study an evolutionary algorithm that locally adapts thresholds and wiring in Random Threshold Networks, based on measurements of a dynamical order parameter. A control parameter p determines the probability of threshold adaptations vs. link rewirings. For any p < 1, we find spontaneous symmetry breaking into a new class of self-organized networks, characterized by a much higher average connectivity K_evo than networks without threshold adaptation (p =1). While K_evo and evolved out-degree distributions are independent from p for p <1, in-degree distributions become broader when p → 1, approaching a power-law. In this limit, time scale separation between threshold adaptions and rewiring also leads to strong correlations between thresholds and in-degree. Finally, evidence is presented that networks converge to self-organized criticality for large N.