Characterization of spatiotemporal chaos in an inhomogeneous active medium

Characterization of spatiotemporal chaos in an inhomogeneous active medium

We study a reaction diffusion system of the activator-inhibitor type with inhomogeneous reaction terms showing spatiotemporal chaos. We analyze the topological properties of the unstable periodic orbits in the slow chaotic dynamics appearing, which can be embedded in three dimensions. We perform a bi-orthogonal decomposition analyzing the minimum number of modes necessary to find the same organ...

Controlling spatiotemporal chaos in active dissipative-dispersive nonlinear systems.

We present an alternative methodology for the stabilization and control of infinite-dimensional dynamical systems exhibiting low-dimensional spatiotemporal chaos. We show that with an appropriate choice of time-dependent controls we are able to stabilize and/or control all stable or unstable solutions, including steady solutions, traveling waves (single and multipulse ones or bound states), and...

Casimir stress in an inhomogeneous medium

The Casimir effect in an inhomogeneous dielectric is investigated using Lifshitz’s theory of electromagnetic vacuum energy. A permittivity function that depends continuously on one Cartesian coordinate is chosen, bounded on each side by homogeneous dielectrics. The result for the Casimir stress is infinite everywhere inside the inhomogeneous region, a divergence that does not occur for piece-wi...

Wave Propagation in an Inhomogeneous Medium

Reflected Waves in an Inhomogeneous Excitable Medium

Propagation can be encumbered in an excitable cable in which intrinsic properties change abruptly. A sudden increase in diameter or a decrease in conductivity or excitability can lead to propagation block or delay in propagation with or without reflection. We study such transient phenomena from a geometric point of view. A simple two-cell caricature, with one cell enlarged to mimic diameter inc...