Studies in self-organised criticality

Statistics of Certain Models of Evolution

In a recent paper, Newman [1] surveys the literature on power law spectra in evolution, self-organised criticality and presents a model of his own to arrive at a conclusion that self-organised criticality is not necessary for evolution. Not only did he miss a key model (Ecolab [2,3]) that has a clear self-organised critical mechanism, but also Newman’s model exhibits the same mechanism that giv...

On the role of self-organised criticality in accretion systems

Self-organised criticality (SOC) has been suggested as a potentially powerful unifying paradigm for interpreting the structure of, and signals from, accretion systems. After reviewing the most promising sites where SOC might be observable, we consider the theoretical arguments for supposing that SOC can occur in accretion discs. Perhaps the most rigorous evidence is provided by numerical modell...

Applying Self-Organised Criticality to Evolutionary Algorithms

Self-organised criticality in base-pair breathing in DNA with a defect

We analyse base-pair breathing in a DNA sequence of 12 base-pairs with a defective base at its centre. We use both all-atom molecular dynamics (MD) simulations and a system of stochastic differential equations (SDE). In both cases, Fourier analysis of the trajectories reveals self-organised critical behaviour in the breathing of base-pairs. The Fourier Transforms (FT) of the interbase distances...

Role of membrane potential fluctuations to the criticality of neuronal avalanche activity

Experimental evidence for self-organised criticality (SOC) in nonconservative systems has recently been found in studies of rat cortical slices. The size distribution of observed neuronal avalanches has been attested to obey 3/2 powerlaw scaling. A mean-field sandpile model of a noisy neuronal system is proposed to refute the irreconcilability between non-conservation and criticality put forwar...