Clustered motion in symplectic coupled map systems

Clustered motion of particles is found in Hamiltonian dynamics of symplectic coupled map systems. Particles assemble and move with strong correlation. The motion is chaotic but is distinguishable from random chaotic motion. Lyapunov analysis distinguishes global instability from local fluctuations. Clustered motions have finite lifetime. They have fractal geometric structure in the phase space, as the orbits are trapped to ruins of KAM tori and islands.