Existence of 'breathers', that is, time-periodic, spatially localized solutions, is proved for a broad range of time-reversible or Hamiltonian networks of weakly coupled oscillators. Some of their… Expand

Part 1 Introduction to area-preserving maps: conservative systems and maps periodic orbits invariant circles stochastic behaviour. Part 2 Introduction to renormalization: renormalization in physics… Expand

We apply some general results for Hamiltonian systems, depending on the notion of signature of eigenvalues, to determine the circumstances under which collisions of imaginary eigenvalue for the… Expand

Gamma-ray bursts (GRBs) are a fascinating cosmological phenomenon. They can last from ten milliseconds to several hours and are often followed by an afterglow at progressively longer wavelengths. T...

SummaryThe idea of surfaces of locally minimal flux is introduced as a key concept for understanding transport in steady three-dimensional, volume-preserving flows. Particular attention is paid to… Expand

We address the issue of spatially localized periodic oscillations in coupled networks - so-called discrete breathers - in a general context. This context is concerned with general conditions which… Expand

This work reviews the present position of and surveys future perspectives in the physics of chaotic advection: the field that emerged three decades ago at the intersection of fluid mechanics and… Expand