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2003
Coupled Ginzburg-Landau equations appear in a variety of contexts involving instabilities in oscillatory media. When the relevant unstable mode is of vectorial character (a common situation in nonlinear optics), the pair of coupled equations has special symmetries and can be written as a vector complex Ginzburg-Landau (CGL) equation. Dynamical properties of localized structures of topological character in this vector-field case are considered. Creation and annihilation processes of different kinds of vector defects are described, and some of them interpreted in theoretical terms. A transition between different regimes of spatiotemporal dynamics is described.
Physical Review E, 2005
The vector complex Ginzburg-Landau equation is an amplitude equation appropriate for describing instabilities in oscillatory media when the order parameter is a vector field ͑for example, laser light or twocomponent Bose condensate͒. It is known that this equation presents a variety of phase singularities or topological defects. We study the parameters that characterize the different kinds of defects and show that the results are useful for a better understanding of the system dynamics.
Computer Physics Communications, 1999
We describe the dynamical behavior found in numerical solutions of the Vector Complex Ginzburg-Landau equation in parameter values where plane waves are stable. Topological defects in the system are responsible for a rich behavior. At low coupling between the vector components, a frozen phase is found, whereas a gas-like phase appears at higher coupling. The transition is a consequence of a defect unbinding phenomena. Entropy functions display a characteristic behavior around the transition.
Physical Review Letters, 2000
Dynamical properties of topological defects in a twodimensional complex vector field are considered. These objects naturally arise in the study of polarized transverse light waves. Dynamics is modeled by a Vector Complex Ginzburg-Landau Equation with parameter values appropriate for linearly polarized laser emission. Creation and annihilation processes, and selforganization of defects in lattice structures, are described. We find "glassy" configurations dominated by vectorial defects and a melting process associated to topological-charge unbinding.
1999
Dynamical properties of topological defects in a twodimensional complex vector field are considered. These objects naturally arise in the study of polarized transverse light waves. Dynamics is modeled by a Vector Complex Ginzburg-Landau Equation with parameter values appropriate for linearly polarized laser emission. Creation and annihilation processes, and selforganization of defects in lattice structures, are described. We find "glassy" configurations dominated by vectorial defects and a melting process associated to topological-charge unbinding.
Physics Letters A, 2000
Coupled Complex Ginzburg-Landau equations describe generic features of the dynamics of coupled fields when they are close to a Hopf bifurcation leading to nonlinear oscillations. We study numerically this set of equations and find, within a particular range of parameters, the presence of uniformly propagating localized objects behaving as coherent structures. Some of these localized objects are interpreted in terms of exact analytical solutions.
Physica D: Nonlinear Phenomena, 2002
We study, analytically and numerically, the dynamical behavior of the solutions of the complex Ginzburg-Landau equation with diffraction but without diffusion, which governs the spatial evolution of the field in an active nonlinear laser cavity. Accordingly, the solutions are subject to periodic boundary conditions. The analysis reveals regions of stable stationary solutions in the model's parameter space, and a wide range of oscillatory and chaotic behaviors. Close to the first bifurcation destabilizing the spatially uniform solution, a stationary single-humped solution is found in an asymptotic analytical form which turns out to be in very good agreement with the numerical results. Simulations reveal a series of stable stationary multi-humped solutions.
Physica D: Nonlinear Phenomena, 1992
An important clement in the long-time dynamics of pattern forming systems is a class of solutions we will call "coherent structures". These are states that are either themselves localized, or that consist of domains of regular patterns connected by localized defects or interfaces. This paper summarizes and extends recent work on such coherent structures in the one-dimensional complex Ginzburg-Landau equation and its generalizations, for which rather complete information can be obtained on the existence and competition of fronts, pulses, sources and sinks. For the special subclass of uniformly translating structures, the solutions are derived from a set of ordinary differential equations that can be interpreted as a flow in a three-dimensional phase space. Fixed points of the flow correspond to the two basic building blocks of coherent structures, uniform amplitude states and evanescent waves whose amplitude decreases smoothly to zero. A study of the stability of the fixed points under the flow leads to results on the existence and multiplicity of the different coherent structures. The dynamical analysis of the original partial differential equation focusses on the competition between pulses and fronts, and is expressed in terms of a set of conjectures for front propagation that generalize the "marginal stability" and "pinch-point" approaches of earlier authors. These rules, together with an exact front solution whose dynamics plays an important role in the selection of patterns, yield an analytic expression for the upper limit of the range of existence of pulse solutions, as well as a determination of the regions of parameter space where uniformly translating fron t solutions can exist. Extensive numerical simulations show consistency with these rules and conjectures for the existence of fronts and pulses. In the parameter ranges where no uniformly translating fronts can exist, examples are shown of irregularly spreading fronts that generate strongly chaotic regions, as well as nonuniformly translating fronts that lead to uniform amplitude states. Recent perturbative treatments based on expansions about the nonlinear Schr6dinger equation are generalized to perturbations of the cubic-quintic and derivative Schr~idinger equations, for which both pulses and fronts exist in the unperturbed system. Comparison of the results with the exact solutions shows that the perturbation theory only yields a subset of the relevant solutions. Nevertheless, those that are obtained are found to be consistent with the general conjectures, and in particular they provide an analytic demonstration of front/pulse competition. While the discussion of the competition between fronts and pulses focusses on the complex Ginzburg-Landau equation with quintic terms and a subcritical bifurcation, a number of results are also presented for the cubic equation. In particular, the existence of a family of moving source solutions derived by Bekki and Nozaki for this equation contradicts the naive counting arguments. We attribute this contradiction to a hidden symmetry of the solution but have not been able to show explicitly how this symmetry affects the phase space orbits.
Physical Review A, 2010
We explore families of spatiotemporal dissipative solitons in a model of three-dimensional (3D) laser cavities including a combination of gain, saturable absorption, and transverse grating. The model is based on the complex Ginzburg-Landau equation with the cubic-quintic nonlinearity and a two-dimensional (2D) periodic potential representing the grating. Fundamental and vortical solitons are found in a numerical form as attractors in this model and their stability against strong random perturbations is tested by direct simulations. The fundamental solitons are completely stable while the vortices, built as rhombus-shaped complexes of four fundamental solitons, may be split by perturbations into their constituents separating in the temporal direction. Nevertheless, a sufficiently strong grating makes the vortices practically stable objects.
Nonlinearity, 2014
In an appropriate moving coordinate frame, source defects are time-periodic solutions to reactiondiffusion equations that are spatially asymptotic to spatially periodic wave trains whose group velocities point away from the core of the defect. In this paper, we rigorously establish nonlinear stability of spectrally stable source defects in the complex Ginzburg-Landau equation. Due to the outward transport at the far field, localized perturbations may lead to a highly non-localized response even on the linear level. To overcome this, we first investigate in detail the dynamics of the solution to the linearized equation. This allows us to determine an approximate solution that satisfies the full equation up to and including quadratic terms in the nonlinearity. This approximation utilizes the fact that the non-localized phase response, resulting from the embedded zero eigenvalues, can be captured, to leading order, by the nonlinear Burgers equation. The analysis is completed by obtaining detailed estimates for the resolvent kernel and pointwise estimates for the Green's function, which allow one to close a nonlinear iteration scheme.
Physical review. E, Statistical, nonlinear, and soft matter physics, 2007
Stable dynamic bound states of dissipative localized structures are found. It is characterized by chaotic oscillations of distance between the localized structures, their phase difference, and the center of mass velocity.
The phenomenon of time-periodic evolution of spatial chaos is investigated in the frames of one-and two-dimensional complex Ginzburg-Landau equations. It is found that there exists a region of the parameters in which disordered spatial distribution of the field behaves periodically in time; the boundaries of this region are determined. The transition to the regime of spatiotemporal chaos is investigated and the possibility of describing spatial disorder by a system of ordinary differential equations is analyzed. The effect of the size of the system on the shape and period of oscillations is investigated. It is found that in the two-dimensional case the regime of time-periodic spatial disorder arises only in a narrow strip, the critical width of which is estimated. The phenomenon investigated in this paper indicates that a family of limit cycles with finite basins exists in the functional phase space of the complex Ginzburg-Landau equation in finite regions of the parameters.
International Journal of Bifurcation and Chaos, 1999
We study the spatiotemporal dynamics, in one and two spatial dimensions, of two complex fields which are the two components of a vector field satisfying a vector form of the complex Ginzburg-Landau equation. We find synchronization and generalized synchronization of the spatiotemporally chaotic dynamics. The two kinds of synchronization can coexist simultaneously in different regions of the space, and they are mediated by localized structures. A quantitative characterization of the degree of synchronization is given in terms of mutual information measures.
Physica D: Nonlinear …, 1992
The dynamical behavior of a large one-dimensional system obeying the cubic complex Ginzburg-Landau equation is studied numerically as a function of parameters near a supercritical bifurcation. Two types of chaotic behavior can be distinguished beyond the Benjamin-Feir instability, a phase turbulence regime with a conserved phase winding number and no phase dislocations (space-time defects), and a defect regime with a nonzero density of defects. The transition between the two can either be continuous or discontinuous (hysteretic), depending on parameters. The spatial decay of the phase correlation function is inferred to be exponential in both regimes, with a sharp decrease of the correlation length upon entering the defect phase. The temporal decay of correlations is exponential in the defect regime.
Periodic evolution of the space chaos in a one-dimensional distributed system represented by the complex Ginzburg-Landau equation is studied. There exists a region of parameters where spatially chaotic distribution of the field varies periodically with time~ and the boundaries of this region are determined. The regime of periodic space chaos was found to exist only for certain initial conditions. A system of ordinary differential equations that describes the space chaos is derived.
Physica D: Nonlinear Phenomena, 1992
An interesting class of physical systems are those that exhibit local gauge symmetries: internal invariances that can be implemented independently at any space-time point. Systems in which these symmetries are spontaneously broken exhibit remarkable properties such as superconductivity, and if such systems also possess spatial symmetry, pattern formation can accompany the gauge symmetry-breaking. We conduct a careful analysis of a well-known example of this phenomenon: the formation of the Abrikosov vortex lattice in the Ginzburg-Landau model of Type-II superconductors. The study of this system has a long history and our principal contribution is to put the analysis rigorously into the context of steady-state equivariant bifurcation theory by the proper implementation of a gauge-fixing procedure. This example may be typical of the way that gauge and spatial symmetries intertwine to produce spatial patterns.
EPL (Europhysics Letters)
The complex Ginzburg-Landau equation with additive noise is a stochastic partial differential equation that describes a remarkably wide range of physical systems which include coupled non-linear oscillators subject to external noise near a Hopf bifurcation instability and spontaneous structure formation in non-equilibrium systems, e.g., in cyclically competing populations or oscillatory chemical reactions. We employ a finite-difference method to numerically solve the noisy complex Ginzburg-Landau equation on a two-dimensional domain with the goal to investigate its non-equilibrium dynamics when the system is quenched into the "defocusing spiral quadrant". We observe slow coarsening dynamics as oppositely charged topological defects annihilate each other, and characterize the ensuing aging scaling behavior. We conclude that the physical aging features in this system are governed by non-universal aging scaling exponents. We also investigate systems with control parameters residing in the "focusing quadrant", and identify slow aging kinetics in that regime as well. We provide heuristic criteria for the existence of slow coarsening dynamics and physical aging behavior in the complex Ginzburg-Landau equation.
Physical Review E, 2006
We introduce a pattern-formation model based on a symmetric system of three linearly coupled cubic-quintic complex Ginzburg-Landau equations, which form a triangular configuration. This is the simplest model of a multicore fiber laser. We identify stability regions for various types of localized patterns possible in this setting, which include stationary and breathing triangular vortices.
Physical Review A, 2010
Complex Ginzburg-Landau (CGL) models of laser media (with the cubic-quintic nonlinearity) do not contain an effective diffusion term, which makes all vortex solitons unstable in these models.
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