Extremal dynamics model on evolving networks

TL;DR

This paper studies an evolving network model with extremal dynamics, revealing self-organized criticality, intermittent activity, and power-law distributions in avalanche sizes and extinction events.

Contribution

It introduces a model combining network evolution with extremal dynamics, demonstrating critical behavior and distinct avalanche regimes.

Findings

Power-law distribution of forward avalanches with two regimes

Intermittent structure in the number of units over time

Power-law distribution of extinction sizes

Abstract

We investigate an extremal dynamics model of evolution with a variable number of units. Due to addition and removal of the units, the topology of the network evolves and the network splits into several clusters. The activity is mostly concentrated in the largest cluster. The time dependence of the number of units exhibits intermittent structure. The self-organized criticality is manifested by a power-law distribution of forward avalanches, but two regimes with distinct exponents tau = 1.98 +- 0.04 and tau^prime = 1.65 +- 0.05 are found. The distribution of extinction sizes obeys a power law with exponent 2.32 +- 0.05.