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Nonlocal turbulent cascades in 2D Gross-Pitaevskii (nonlinear Schrodinger) equation

September 30, 2014
Abstract
Natalia Vladimirova University of New Mexico Difficulty in understanding turbulence in 2D Gross-Pitaevsky model is related to the fact that the spectra of both inverse and direct cascades in weak-turbulence approximation carry fluxes of a wrong sign and cannot be realized. We derived analytically the exact flux constancy laws (analogs of Kolmogorov's 4/5-law), expressed via the fourth-order moment and valid for any nonlinearity. We confirmed the flux laws in direct numerical simulations. We show that a constant flux is realized by non-local wave interaction both in direct and inverse cascades. Wave spectra (second-order moments) are close to slightly (logarithmically) distorted thermal equilibrium in both cascades.
Supplementary Materials