Cosmic rays scatter off magnetic irregularities (Alfvén waves) with which they are resonant, that is, waves of wavelength comparable to their gyroradii. These waves may be generated either by the cosmic rays themselves, if they stream faster than the Alfvén speed, or by sources of MHD turbulence. Waves excited by streaming cosmic rays are ideally shaped for scattering, whereas the scattering ef...

MHD equations are presented for the mixture of superfluid neutrons, superconducting protons, and normal electrons believed to exist in the outer cores of neutron stars. The dissipative effects of electron viscosity and mutual friction due to electron-vortex scattering are also included. It is shown that Alfvén waves are replaced by cyclotronvortex waves that have not been previously derived fro...

Propagation of torsional Alfvén waves along magnetic flux tubes has been extensively studied for many years, but no conclusive results regarding the existence of a cutoff frequency for these waves have been obtained. The main purpose of this paper is to derive new wave equations that describe the propagation of linear torsional Alfvén waves along thin and isothermal magnetic flux tubes and to u...

The interpretation of simultaneous ionospheric Doppler sounding and ground magnetometer observations of low-latitude Pi2 waves is revised. We compare the theoretical estimates of the ionospheric Doppler velocity for the same amplitude of the ground magnetic disturbances produced by a large-scale compressional mode and an Alfvén mode. The plasma vertical displacement caused by the wave electric ...

This paper presents an analytical investigation of the nonlinear interaction of phase-mixed Alfvén waves in the framework of two-fluid magnetohydrodynamics. It focuses on the parametric decay of the phase-mixed pump Alfvén wave into two daughter Alfvén waves. This parametric decay is a nonlinear phenomenon which does not occur in ideal MHD since it is induced by the combined action of finite wa...

Magnetohydrodynamic (MHD) waves in the solar wind and magnetosphere are propagated in a medium whose velocity is comparable to or greater than the wave velocity and which varies in both space and time. In the approximation where the scales of the time and space variation are long compared with the period and wavelength, the ray-tracing equations can be generalized and then include an additional...

We review recent results obtained in [14] on weak turbulence of shear-Alfvén waves in the limit of strongly anisotropic pulsations that are elongated along a strong external magnetic field. The kinetic equation for energy is presented at the level of three-wave interactions. It is in agreement with the Galtier et al. [13] formulation of the full three–dimensional helical case when taking the pr...