We discuss a family of clusters C corresponding to the region whose boundary is formed by a fractional Brownian path y(i) and by the moving average function yn(i)≡1n∑k=0n−1y(i−k). Our model generates fractal directed patterns showing spatio-temporal complexity, and we demonstrate that...

A method for obtaining critical properties is presented. Based on self-organized criticality, it drives the system spontaneously to the critical point, providing an efficient way to estimate critical properties. The method is illustrated for Ising spin systems, and despite the small lattice...

We study the spin-1 Ising model with non-local constraints imposed by the Bak–Tang–Wiesenfeld sandpile model of self-organized criticality (SOC). The model is constructed as if the sandpile is being built on a (honeycomb) lattice with Ising interactions. In this way we combine two models...

The temporal characteristics of the sea-ice motion were analyzed using the GPS-monitoring carried out during a drift of the ice camp “North Pole 32” in 2003. The detected accelerations of the ice field were found to be correlated in time. The energy release due to impact interactions between...

We define the BTW mechanism on a two-dimensional heterogeneous self-similar lattice. Our model exhibits the power distribution of avalanches with the exponent τ=2−2/ν, where ν is the similarity exponent of the lattice. The inequality τ1, for the first time detected in this paper inside a...

We study a one-dimensional sandpile model in small-world networks with long-range links either by introducing them randomly to fixed connection topology (quenched randomness) or to temporary connection topology (annealed randomness) between cells to allow a grain to topple from a cell to a...

The partitioning of random graphs is investigated numerically using “simulated annealing” and “extremal optimization”. While generally in an NP-hard problem, it is shown that the optimization of the graph partitions is particularly difficult for sparse graphs with average connectivities...

We show that correlated dynamics and long time memory persist in self-organized criticality (SOC) systems even when forced away from the defined critical point that exists at vanishing drive strength. These temporal correlations are found for all levels of external forcing as long as the system...

The oldest answered question in the social sciences is ‘Why do societies collapse?’. I advance a theory of the collapse of societies that is based on self-organized criticality, which is a nonlinear process that produces sudden shifts and fractal patterns in historical time series....