Observation of Conservations Laws in Diffusion Limited AggregationWe repeat the numerical experiments for diffusion limited aggregation (DLA) and show that there is a potentially infinite set of conserved quantities for the long time asymptotics. We connect these…Mark B. Mineev-Weinstein, Ronnie Mainieri·Dec 6, 1994SaveLearn
Defect Dynamics for Spiral Chaos in Rayleigh-Benard ConvectionA theory of the novel spiral chaos state recently observed in Rayleigh-Benard convection is proposed in terms of the importance of invasive defects i.e defects that through their intrinsic dynamics…M. C. Cross, Yuhai Tu·Dec 1, 1994SaveLearn
On the validity of mean-field amplitude equations for counterpropagating wavetrainsWe rigorously establish the validity of the equations describing the evolution of one-dimensional long wavelength modulations of counterpropagating wavetrains for a hyperbolic model equation, namely…R. D. Pierce, C. E. Wayne·Nov 29, 1994SaveLearn
Front propagation into unstable and metastable states in Smectic C* liquid crystals: linear and nonlinear marginal stability analysisWe discuss the front propagation in ferroelectric chiral smectics (SmC*) subjected to electric and magnetic fields applied parallel to smectic layers. The reversal of the electric field induces the…Wim van Saarloos, Martin van Hecke, Robert Holyst·Nov 16, 1994SaveLearn
A Variational Principle for the Asymptotic Speed of Fronts of the Density Dependent Diffusion--Reaction EquationWe show that the minimal speed for the existence of monotonic fronts of the equation ut = (um)xx + f(u) with f(0) = f(1) = 0, m >1 and f>0 in (0,1) derives from a variational…R. D. Benguria, M. C. Depassier·Oct 27, 1994SaveLearn
Bipolar Electrodiffusion model for Electroconvection in NematicsThe common description of the electrical behavior of a nematic liquid crystal as an anisotropic dielectric medium with (weak) ohmic conductivity is extended to an electrodiffusion model with two…Martin Treiber, Lorenz Kramer·Sep 23, 1994SaveLearn
Jam phases in two-dimensional cellular automata model of traffic flowThe jam phases in a two-dimensional cellular automata model of traffic flow are investigated by computer simulations. Two different types of the jam phases are found. The spatially diagonal…Shin-ichi Tadaki, Macoto Kikuchi·Sep 22, 1994SaveLearn
From the defocusing nonlinear Schroedinger to the complex Ginzburg-Landau equationPerturbation approaches developed so far for the dark soliton solutions of the (fully integrable) defocusing nonlinear Schroedinger equation cannot describe the dynamics resulting from dissipative…Olaf Stiller, Stefan Popp, Lorenz Kramer·Sep 17, 1994SaveLearn
Hole Solutions in the 1d Complex Ginzburg-Landau EquationThe cubic Complex Ginzburg-Landau Equation (CGLE) has a one parameter family of traveling localized source solutions. These so called 'Nozaki-Bekki holes' are (dynamically) stable in some…Stefan Popp, Olaf Stiller, Igor Aranson et al.·Sep 17, 1994SaveLearn
Bound Pairs of Fronts in a Real Ginzburg-Landau Equation Coupled to a Mean FieldMotivated by the observation of localized traveling-wave states (`pulses') in convection in binary liquid mixtures, the interaction of fronts is investigated in a real Ginzburg-Landau equation…Henar Herrero, Hermann Riecke·Sep 6, 1994SaveLearn
Variational Characterization of the Speed of Propagation of Fronts for the Nonlinear Diffusion EquationWe give an integral variational characterization for the speed of fronts of the nonlinear diffusion equation ut = uxx + f(u) with f(0)=f(1)=0, and f>0 in (0,1), which permits, in…R. D. Benguria, M. C. Depassier·Sep 1, 1994SaveLearn
Universal trapping scaling on the unstable manifold for a collisionless electrostatic modeAn amplitude equation for an unstable mode in a collisionless plasma is derived from the dynamics on the two-dimensional unstable manifold of the equilibrium. The mode amplitude ρ(t) decouples from…John David Crawford·Jul 6, 1994SaveLearn
The Korteweg-de Vries Hierarchy and Long Water-WavesBy using the multiple scale method with the simultaneous introduction of multiple times, we study the propagation of long surface-waves in a shallow inviscid fluid. As a consequence of the…R. A. Kraenkel, M. A. Manna, J. G. Pereira·Jun 17, 1994SaveLearn
Complex Patterns in Reaction-Diffusion Systems: A Tale of Two Front InstabilitiesTwo front instabilities in a reaction-diffusion system are shown to lead to the formation of complex patterns. The first is an instability to transverse modulations that drives the formation of…Aric Hagberg, Ehud Meron·May 26, 1994SaveLearn
New Sets of Kink Bearing HamiltoniansGiven a kink bearing Hamiltonian, Isospectral Hamiltonian approach is used in generating new sets of Hamiltonains which also admit kink solutions. We use Sine-Gordon model as a example and explicitly…B. Dey, C. N. Kumar·Apr 28, 1994SaveLearn
Normal Form, Symmetry and Infinite Dimensional Lie Algebra for System of Ode'sThe normal form for a system of ode's is constructed from its polynomial symmetries of the linear part of the system, which is assumed to be semi-simple. The symmetries are shown to have a simple…Yuji Kodama·Apr 27, 1994SaveLearn
Dynamic Front Transitions and Spiral-Vortex NucleationThis is a study of front dynamics in reaction diffusion systems near Nonequilibrium Ising-Bloch bifurcations. We find that the relation between front velocity and perturbative factors, such as…Christian Elphick, Aric Hagberg, Ehud Meron·Apr 25, 1994SaveLearn
Example of shock wave in unstaible medium: The focusing nonlinear Schrodinger equationDissipationless shock waves in modulational unstable one-dimensional medium are investigated on the simplest example of integrable focusing nonlinear Schr\''odinger (NS) equation. Our…Ramil' F. Bikbaev, Vadim R. Kudashev·Apr 21, 1994SaveLearn
Whitham deformations partially saturating the modulational instability in the nonlinear Schrodinger equationIn the framework of Gurevich and Pitaevskii approach [1] we construct modulated by Whitham [2] solution of nonlinear Shrodinger (NS) equation partially saturating the modulational instability. This…Ramil' F. Bikbaev, Vadim R. Kudashev·Apr 20, 1994SaveLearn
KdV shock-like waves as invariant solutions of KdV equation symmetriesWe consider the following hypothesis: some of KdV equation shock-like waves are invariant with respect to the combination of the Galilean symmetry and KdV equation higher symmetries. Also we…Vadim R. Kudashev·Apr 7, 1994SaveLearn
Inverse ac Josephson Effect for a Fluxon in a Long Modulated JunctionWe analyze motion of a fluxon in a weakly damped ac-driven long Josephson junction with a periodically modulated maximum Josephson current density. We demonstrate both analytically and numerically…Giovanni Filatrella, Boris A. Malomed, Robert D. Parmentier·Mar 30, 1994SaveLearn
Kinks in the Presence of Rapidly Varying PerturbationsDynamics of sine-Gordon kinks in the presence of rapidly varying periodic perturbations of different physical origins is described analytically and numerically. The analytical approach is based on…Yuri S. Kivshar, Niels Gr\{o}nbech-Jensen, Robert D. Parmentier·Mar 30, 1994SaveLearn
New exact fronts for the nonlinear diffusion equation with quintic nonlinearitiesWe consider travelling wave solutions of the reaction diffusion equation with quintic nonlinearities ut = uxx + μu (1 -u ) ( 1 +αu + βu2 +γu3). If the parameters α, β and γ obey a special…R. D. Benguria, M. C. Depassier·Mar 21, 1994SaveLearn
Asymptotic expansion for layer solutions of a singularly perturbed reaction-diffusion systemFor a singularly perturbed system of reaction--diffusion equations, assuming that the 0th order solutions in regular and singular regions are all stable, we construct matched asymptotic expansions…Xiao-Biao Lin·Mar 18, 1994SaveLearn
On the validity of the linear speed selection mechanism for fronts of the nonlinear diffusion equationWe consider the problem of the speed selection mechanism for the one dimensional nonlinear diffusion equation ut = uxx + f(u). It has been rigorously shown by Aronson and Weinberger that for a…R. D. Benguria, M. C. Depassier·Mar 8, 1994SaveLearn