Narrow Results

It is shown that pulses in the complete quintic one-dimensional Ginzburg–Landau equation with complex coefficients appear through a saddle-node bifurcation which is determined analytically through a suitable approximation of the explicit form of the pulses. The results are in excellent agreement with direct numerical simulations.

We present an experimental study of the generation of strongly localized structures that propagate on the surface of a dissipative fluid. We excited a layer of fluid with a vertical periodic acceleration field, and a parametric instability occurs when a certain threshold value is achieved. This process is known as Faraday Instability and the temporal evolution of the system obeys a period-doubling route. For a highly dissipative fluid we observed two new interesting phenomena: the generation of high spatially localized structures which propagate on top of the stripes of stationary pattern, and a periodic window which occurs after the system reached spatiotemporal chaos.

Bazykin proposed a Lotka–Volterra-type ecological model that accounts for simplified territoriality, which neither depends on territory size nor on food availability. In this study, we describe the global dynamics of the Bazykin model using analytical and numerical methods. We specifically focus on the effects of mutual predator interference and the prey carrying capacity since the variability of each could have especially dramatic ecological repercussions. The model displays a broad array of complex dynamics in space and time; for instance, we find the coexistence of a limit cycle and a steady state, and bistability of steady states. We also characterize super- and subcritical Poincaré–Andronov–Hopf bifurcations and a Bogdanov–Takens bifurcation. To illustrate the system's ability to naturally shift from stable to unstable dynamics, we construct bursting solutions, which depend on the slow dynamics of the carrying capacity. We also consider the stabilizing effect of the intraspecies interaction parameter, without which the system only shows either a stable steady state or oscillatory solutions with large amplitudes. We argue that this large amplitude behavior is the source of chaotic behavior reported in systems that use the MacArthur–Rosenzweig model to describe food-chain dynamics. Finally, we find the sufficient conditions in parameter space for Turing patterns and obtain the so-called "back-eye" pattern and localized structures.

Transition from motionless to moving domain walls connecting two uniform oscillatory equivalent states in both a magnetic wire forced with a transversal oscillating magnetic field and a parametrically driven damped pendula chain are studied. These domain walls are not contained in the conventional approach to these systems — parametrically driven damped nonlinear Schrödinger equation. By adding in this model higher order terms, we are able to explain these solutions and the transition between resting and moving walls. Based on amended amplitude equation, we deduced a set of ordinary differential equations which describes the nonvariational Ising–Bloch transition in unified manner.

We study the process of localization of a hexagonal pattern in a uniform background, specifically, the role played by the shape and size of the domain where the hexagonal pattern is confined. We base our analysis on a numerical study of a Swift–Hohenberg type equation (which exhibits coexistence between hexagons and a uniform state), and in a scale expansion to estimate the stress undergoing by the interface (the curve that separates the hexagonal phase from the uniform one). Our scaling approach supplies us a good physical picture of what we observe numerically.

The dynamics of an interface connecting a stationary stripe pattern with a homogeneous state is studied. The conventional approach which describes this interface, Newell–Whitehead–Segel amplitude equation, does not account for the rich dynamics exhibited by these interfaces. By amending this amplitude equation with a nonresonate term, we can describe this interface and its dynamics in a unified manner. This model exhibits a rich and complex transversal dynamics at the interface, including front propagations, transversal patterns, locking phenomenon, and transversal localized structures.

A particular type of localized structure in a prototypical model for population dynamics interaction is studied. The model considers cooperative and competitive interaction among the individuals. Interaction at distance (or nonlocal interaction) and a simple random walk for the motion of the individuals are included. The system exhibits the formation of a periodic cellular pattern in some region of its parameter space. Inside this parameter region, it is possible to observe the localization of a single cell from the cellular pattern into an unpopulated background. The stability of this localized structure is discussed, as well as the destabilization process that gives rise to its own self-replication, inducing the propagation of the cellular pattern. The long distance interaction between these localized structures is also studied which results in a mutual repulsion.