The books in this series will focus on the recent developments, findings and progress on fundamental theories and principles, analytical and symbolic approaches, computational techniques in nonlinear physical science and nonlinear mathematics.Topics of interest in Complexity, Nonlinearity and Chaos include but not limited to:· New findings and discoveries in nonlinear physics and mathematics, · Complexity and mathematical structures in nonlinear physics, · Nonlinear phenomena and observations in nature, · Computational methods and simulations in complex systems, · New theories, and principles and mathematical methods, · Stability, bifurcation, chaos and fractals in nonlinear physical science.

The books in this series will focus on the recent developments, findings and progress on fundamental theories and principles, analytical and symbolic approaches, computational techniques in nonlinear physical science and nonlinear mathematics.Topics of interest in Complexity, Nonlinearity and Chaos include but not limited to:· New findings and discoveries in nonlinear physics and mathematics, · Complexity and mathematical structures in nonlinear physics, · Nonlinear phenomena and observations in nature, · Computational methods and simulations in complex systems, · New theories, and principles and mathematical methods, · Stability, bifurcation, chaos and fractals in nonlinear physical science.

No abstract

Dynamics of an atomic wavepacket in an optical superlattice is considered. We propose a simple scheme of wavepacket localization near the minima of the optical potential. In our approach, a wavelike perturbation caused by an additional lattice induces classical resonance which traps an atomic cloud. Adiabatic phase modulation of the perturbation slowly shifts resonance zone in phase space to the range of lower energies, retaining trapped atoms inside. This phenomenon is a kind of autoresonance. Quantum computations agree well with classical modelling.

The motion of oscillatorylike nonlinear Hamiltonian systems, driven by a weak noise, is considered. A general method to find regions of stability in the phase space of a randomly driven system, based on a specific Poincaré map, is proposed and justified. Physical manifestations of these regions of stability are coherent clusters. We illustrate the method and demonstrate the appearance of coherent clusters with two models motivated by the problems of waveguide sound propagation and Lagrangian mixing of passive scalars in the ocean. We find bunches of sound rays propagating coherently in an underwater waveguide through a randomly fluctuating ocean at long distances. We find clusters of passive particles to be advected coherently for a comparatively long time by a random two-dimensional flow modeling mixing around a fixed vortex.