title: Energy decay laws in strongly anisotropic magnetohydrodynamic turbulence.
abstract: We investigate the influence of a uniform magnetic field B(0)=B(0)e( parallel) on energy decay laws in incompressible magnetohydrodynamic (MHD) turbulence. The nonlinear transfer reduction along B(0) is included in a model that distinguishes parallel and perpendicular directions, following a phenomenology of Kraichnan. We predict a slowing down of the energy decay due to anisotropy in the limit of strong B(0), with distinct power laws for energy decay of shear- and pseudo-Alfvén waves. Numerical results from the kinetic equations of Alfvén wave turbulence recover these predictions, and MHD numerical results clearly tend to follow them in the lowest perpendicular planes.
authors: Institut d'Astrophysique Spatiale, Bâtiment 121, F-91405 Orsay (France); Université Paris-Sud XI and CNRS (UMR 8617), France.
authors: Barbara
authors: B
authors: Bigot
authors: Sébastien
authors: S
authors: Galtier
authors: Hélène
authors: H
authors: Politano