ha o - dy n / 99 11 02 1 v 1 1 6 N ov 1 99 9 Almost Periodic Passive Tracer Dispersion ∗

ha o - dy n / 98 05 02 1 v 1 2 5 M ay 1 99 8 Passive Tracer Dispersion with Random or Periodic Source ∗

In this paper, the author investigates the impact of external sources on the pattern formation and long-time behavior of concentration profiles of passive tracers in a two-dimensional shear flow. It is shown that a time-periodic concentration profile exists for time-periodic external source, while for random source, the distribution functions of all concentration profiles weakly converge to a u...

ar X iv : c ha o - dy n / 99 11 02 5 v 1 1 8 N ov 1 99 9 General properties of propagation in chaotic systems

We conjecture that in one-dimensional spatially extended systems the propagation velocity of correlations coincides with a zero of the convective Lyapunov spectrum. This conjecture is successfully tested in three different contexts: (i) a Hamiltonian system (a Fermi-Pasta-Ulam chain of oscillators); (ii) a general model for spatio-temporal chaos (the complex Ginzburg-Landau equation); (iii) exp...

ar X iv : c ha o - dy n / 99 03 01 4 v 1 9 M ar 1 99 9 Transport in finite size systems : an exit time approach

In the framework of chaotic scattering we analyze passive tracer transport in finite systems. In particular, we study models with open streamlines and a finite number of recirculation zones. In the non trivial case with a small number of recirculation zones a description by mean of asymptotic quantities (such as the eddy diffusivity) is not appropriate. The non asymptotic properties of dispersi...

ha o - dy n / 99 06 02 5 v 1 1 5 Ju n 19 99 Dynamics near Resonance Junctions in Hamiltonian Systems

An approximate Poincare map near equally strong multiple resonances is reduced by means the method of averaging. Near the resonance junction of three degrees of freedom, we find that some homoclinic orbits “whiskers” in single resonance lines survive and form nearly periodic orbits, each of which looks like a pair of homoclinic orbits.

ar X iv : c ha o - dy n / 99 10 00 5 v 1 6 O ct 1 99 9 The Finite - Difference Analysis and Time Flow