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Related papers: Pulsating and rotating spirals in a delayed feedba…

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We investigate a diffusive, stage-structured epidemic model with the maturation delay and freely-moving delay. Choosing delays and diffusive rates as bifurcation parameters, the only possible way to destabilize the endemic equilibrium is…

Dynamical Systems · Mathematics 2018-05-25 Yanfei Du , Ben Niu , Junjie Wei

We present a bifurcation analysis of a normal form for travelling waves in one-dimensional excitable media. The normal form which has been recently proposed on phenomenological grounds is given in form of a differential delay equation. The…

Pattern Formation and Solitons · Physics 2009-11-13 G. A. Gottwald

We consider the non-monotone degenerate diffusion equation with time delay. Different from the linear diffusion equation, the degenerate equation allows for semi-compactly supported traveling waves. In particular, we discover…

Analysis of PDEs · Mathematics 2020-06-24 Tianyuan Xu , Shanming Ji , Ming Mei , Jingxue Yin

A parameter dependent perturbation of the spectrum of the scalar Laplacian is studied for a class of nonlocal and non-self-adjoint rank one perturbations. A detailed description of the perturbed spectrum is obtained both for Dirichlet…

Analysis of PDEs · Mathematics 2020-07-10 Patrick Guidotti , Sandro Merino

We have found a way for penetrating the space of the dynamical systems towards systems of arbitrary dimension exhibiting the nonlinear mixing of a large number of oscillation modes through which extraordinarily complex time evolutions…

Adaptation and Self-Organizing Systems · Physics 2024-06-26 R. Herrero , J. Farjas , F. Pi , G. Orriols

In this note, we study the long-time dynamics of passive scalars driven by rotationally symmetric flows. We focus on identifying precise conditions on the velocity field in order to prove enhanced dissipation and Taylor dispersion in…

Analysis of PDEs · Mathematics 2023-05-30 Michele Coti Zelati , Michele Dolce , Chia-Chun Lo

This paper is devoted to the study of the stability of limit cycles of a nonlinear delay differential equation with a distributed delay. The equation arises from a model of population dynamics describing the evolution of a pluripotent stem…

Analysis of PDEs · Mathematics 2009-04-17 Mostafa Adimy , Fabien Crauste , Andrei Halanay , Mihaela Neamtu , Dumitru Opris

We present a method to control the two-dimensional shape of traveling wave solutions to reaction-diffusion systems, as e.g. interfaces and excitation pulses. Control signals that realize a pre-given wave shape are determined analytically…

Pattern Formation and Solitons · Physics 2014-12-15 Jakob Löber , Steffen Martens , Harald Engel

In a weakly excitable medium, characterized by a large threshold stimulus, the free end of an isolated broken plane wave (wave tip) can either rotate (steadily or unsteadily) around a large excitable core, thereby producing a spiral…

Soft Condensed Matter · Physics 2009-10-31 Vincent Hakim , Alain Karma

Spiral waves in active media react to small perturbations as particle-like objects. Here we apply the asymptotic theory to the interaction of spiral waves with a localized inhomogeneity, which leads to a novel prediction: drift of the…

Pattern Formation and Solitons · Physics 2010-01-25 V. N. Biktashev , D. Barkley , I. V. Biktasheva

We prove existence of spiral waves in oscillatory media with nonlocal coupling. Our starting point is a nonlocal complex Ginzburg-Landau (cGL) equation, rigorously derived as an amplitude equation for integro-differential equations…

Analysis of PDEs · Mathematics 2024-01-30 Gabriela Jaramillo

We examine the general question of statistical changes experienced by ensembles of nonlinear random waves propagating in systems ruled by integrable equations. In our study that enters within the framework of integrable turbulence, we…

Optics · Physics 2016-08-24 S. Randoux , P. Walczak , M. Onorato , P. Suret

Electrical waves in the heart form rotating spiral or scroll waves during life-threatening arrhythmias such as atrial or ventricular fibrillation. The wave dynamics are typically modeled using coupled partial differential equations, which…

Medical Physics · Physics 2024-10-07 Tanish Baranwal , Jan Lebert , Jan Christoph

Double Hopf bifurcation analysis can be used to reveal some complicated dynamical behavior in a dynamical system, such as the existence or coexistence of periodic orbits, quasi-periodic orbits, or even chaos. In this paper, an algorithm for…

Dynamical Systems · Mathematics 2018-11-27 Yanfei Du , Ben Niu , Yuxiao Guo , Junjie Wei

The presence of spiral structure in isolated galaxies is a problem that has only been partially explained by theoretical models. Because the rate and pattern of star formation in the disk must depend only on mechanisms internal to the disk,…

Astrophysics · Physics 2009-11-06 D. Cartin , G. Khanna

Coupled wave equations are popular tool for investigating longitudinal dynamical effects in semiconductor lasers, for example, sensitivity to delayed optical feedback. We study a model that consists of a hyperbolic linear system of partial…

Dynamical Systems · Mathematics 2013-08-12 Jan Sieber

Spiral waves arise in many biological, chemical, and physiological systems. The kinematical model can be used to describe the motion of the spiral arms approximated as curves in the plane. For this model, there appeared some results in the…

Dynamical Systems · Mathematics 2007-05-23 Chu-Pin Lo , Nedialko S. Nedialkov , Juan-Ming Yuan

The spiking properties of a subcritical Hopf oscillator with a time delayed nonlinear feedback is investigated. Finite time delay is found to significantly affect both the statistics and the fine structure of the spiking behavior. These…

Chaotic Dynamics · Physics 2009-11-11 Gautam C Sethia , Abhijit Sen

We derive new, explicit representations for the solution to the scalar wave equation in the exterior of a sphere, subject to either Dirichlet or Robin boundary conditions. Our formula leads to a stable and high-order numerical scheme that…

Numerical Analysis · Mathematics 2015-06-16 Leslie Greengard , Thomas Hagstrom , Shidong Jiang

People have been familiar with the phenomenon of wave refraction for several centuries. Recently, a novel type of refraction, i.e., negative refraction, where both incident and refractory lines locate on the same side of the normal line,…

Other Condensed Matter · Physics 2009-11-13 Zhoujian Cao , Hong Zhang , Gang Hu