C J Boulter

Learn More
We use extensive numerical simulations to test recent claims of universality in the nonconservative regime of the Olami-Feder-Christensen model. By studying larger systems and a wider range of dissipation levels than previously considered we conclude that there is no evidence of universality in the model with only limited regions of the event size(More)
The Olami-Feder-Christensen model is a simple lattice based cellular automaton model introduced as a prototype to study self-organization in systems with a continuous state variable. Despite its simplicity there remains controversy over whether the system is truly critical in the nonconservative regime. Here we address this issue by introducing the layer(More)
The avalanche size distribution and supercritical toppling value distribution in the Olami-Feder-Christensen model are examined, demonstrating that there exists a crossover value alpha(X) approximately 0.14 for the conservation parameter in the model. We have further confirmed the location of this crossover by identifying upper and lower bounds for(More)
An extensive study of the effect of fluctuations on the unbinding of an interface from a wall in a ternary system is presented. The framework upon which the analysis is based is a linear functional renormalization group scheme of the appropriate effective interface Hamiltonian. The interface model includes position-dependent gradient coefficients, and their(More)
The wetting behavior of a ternary mixture of oil, water, and amphiphile in the presence of a surface is studied. An interface model carefully derived from an underlying Ginzburg-Landau theory is introduced, which contains position dependent rigidity and stiffness coefficients. Using this model we predict a rich surface phase diagram containing thin-thick,(More)
We propose that an appropriate prototype for modeling self-organized criticality in dissipative systems is a generalized version of the two-variable cellular automata model introduced by Hergarten and Neugebauer [Phys. Rev. E 61, 2382 (2000)]. We show that the model predicts exponents for the event size distribution which are consistent with physically(More)
In this paper we determine the wetting phase diagram for three-dimensional systems with short-range forces assuming the presence of a position-dependent stiffness contribution as recently proposed [M.E. Fisher and A.J. Jin, Phys. Rev. Lett. 69, 792 (1992)]. We predict a discontinuous transformation of the phase diagram immediately upon moving beyond the(More)
  • 1