Stochastic linearization of turbulent dynamics of dispersive waves in equilibrium and non-equilibrium state

• Published in: New journal of physics 2016-08, Vol.18 (8), p.83028
• Main Authors: Jiang, Shixiao W, Lu, Haihao, Zhou, Douglas, Cai, David
• Format: Article
• Language: English
• Subjects: effective linear stochastic structure; Equilibrium; Fermi-Pasta-Ulam chain; long-wavelength renormalized waves; nonequilibrium steady state; Nonlinear dynamics; Nonlinear optics; Nonlinear systems; Ocean dynamics; Physics; Plasma physics; Plasmas (physics); Steady state; Turbulence; Wave dispersion; β-Fermi–Pasta–Ulam chain
• ISSN: 1367-2630; 1367-2630
• DOI: 10.1088/1367-2630/18/8/083028

Characterizing dispersive wave turbulence in the long time dynamics is central to understanding of many natural phenomena, e.g., in atmosphere ocean dynamics, nonlinear optics, and plasma physics. Using the β-Fermi-Pasta-Ulam nonlinear system as a prototypical example, we show that in thermal equilibrium and non-equilibrium steady state the turbulent state even in the strongly nonlinear regime possesses an effective linear stochastic structure in renormalized normal variables. In this framework, we can well characterize the spatiotemporal dynamics, which are dominated by long-wavelength renormalized waves. We further demonstrate that the energy flux is nearly saturated by the long-wavelength renormalized waves in non-equilibrium steady state. The scenario of such effective linear stochastic dynamics can be extended to study turbulent states in other nonlinear wave systems.