Large dispersion, averaging and attractors: three 1D paradigms

TL;DR

This paper investigates how large dispersion terms influence the dynamics of 1D dissipative equations, revealing three distinct scenarios where dispersion either suppresses, preserves, or destroys complex dynamics and attractor structures.

Contribution

It classifies and analyzes three different regimes of large dispersion effects on 1D dissipative systems, providing new insights into their long-term behavior.

Findings

Large dispersion can suppress non-trivial dynamics, leading to gradient systems.

In some regimes, large dispersion does not affect the chaotic nature of the system.

Large dispersion can also destroy dissipation, enlarging the attractor size.

Abstract

The effect of rapid oscillations, related to large dispersion terms, on the dynamics of dissipative evolution equations is studied for the model examples of the 1D complex Ginzburg-Landau and the Kuramoto-Sivashinsky equations. Three different scenarios of this effect are demonstrated. According to the first scenario, the dissipation mechanism is not affected and the diameter of the global attractor remains uniformly bounded with respect to the very large dispersion coefficient. However, the limit equation, as the dispersion parameter tends to infinity, becomes a gradient system. Therefore, adding the large dispersion term actually suppresses the non-trivial dynamics. According to the second scenario, neither the dissipation mechanism, nor the dynamics are essentially affected by the large dispersion and the limit dynamics remains complicated (chaotic). Finally, it is demonstrated in the third scenario that the dissipation mechanism is completely destroyed by the large dispersion, and that the diameter of the global attractor grows together with the growth of the dispersion parameter.