Alfven Wave Collisions, The Fundamental Building Block of Plasma Turbulence II: Numerical Solution

TL;DR

This paper numerically verifies an analytical model of Alfven wave interactions, demonstrating that incompressible MHD solutions accurately capture nonlinear energy transfer in weakly collisional plasma turbulence.

Contribution

It provides the first numerical verification of an asymptotic analytical solution for Alfven wave collisions in plasma turbulence, bridging theory and simulation.

Findings

Analytical solution agrees with gyrokinetic simulation

Incompressible MHD describes key nonlinear dynamics

Validates weak turbulence limit assumptions

Abstract

This paper presents the numerical verification of an asymptotic analytical solution for the nonlinear interaction between counterpropagating Alfven waves, the fundamental building block of astrophysical plasma turbulence. The analytical solution, derived in the weak turbulence limit using the equations of incompressible MHD, is compared to a nonlinear gyrokinetic simulation of an Alfven wave collision. The agreement between these methods signifies that the incompressible solution satisfactorily describes the essential dynamics of the nonlinear energy transfer, even under the weakly collisional plasma conditions relevant to many astrophysical environments.