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## Full-Text Articles in Physics

Critical Dynamics Of Nonconserved Ising-Like Systems, K. E. Bassler, Beate Schmittmann

#### Critical Dynamics Of Nonconserved Ising-Like Systems, K. E. Bassler, Beate Schmittmann

*Beate Schmittmann*

We show that the dynamical fixed point of Ising-like models, characterized by a single scalar, nonconserved ordering field, is stable near four dimensions with respect to all dynamic perturbations, including those of a nonequilibrium nature.

Spontaneous Structure Formation In Driven Systems With Two Species: Exact Solutions In A Mean-Field Theory, I. Vilfan, R. K. P. Zia, Beate Schmittmann

#### Spontaneous Structure Formation In Driven Systems With Two Species: Exact Solutions In A Mean-Field Theory, I. Vilfan, R. K. P. Zia, Beate Schmittmann

*Beate Schmittmann*

A stochastic lattice gas of particles, subject to an excluded volume constraint and to a uniform external driving field, is investigated. Using a mean-field theory for a system with equal number of oppositely charged particles, exact results are obtained. Focusing on the current-vs-density plot, we propose an explanation for the discontinuous transition found in earlier simulations. A critical value of the drive, below which this transition becomes continuous, is found. These results are supported by a bifurcation analysis, leading to an equation of motion for the amplitude of the soft mode.

Renormalization-Group Study Of A Hybrid Driven Diffusive System, K. E. Bassler, Beate Schmittmann

#### Renormalization-Group Study Of A Hybrid Driven Diffusive System, K. E. Bassler, Beate Schmittmann

*Beate Schmittmann*

We consider a d-dimensional stochastic lattice gas of interacting particles, diffusing under the influence of a short-ranged, attractive Ising Hamiltonian and a ‘‘hybrid’’ external field which is a superposition of a uniform and an annealed random drive, acting in orthogonal subspaces of dimensions one and m, respectively. Driven into a nonequilibrium steady state, the half-filled system phase segregates via a continuous transition at a field-dependent critical temperature. Using renormalization-group techniques, we show that its critical behavior falls into a new universality class with upper critical dimension dc=5-m, characterized by two distinct anisotropy exponents, which, like all other indices, are ...