Comment on 'Alfven Instability in a Compressible Flow' [Phys. Rev. Lett. 101, 245001 (2008)]
arXiv:0904.4384 · doi:10.1103/PhysRevLett.103.019501
Abstract
In a recent paper [Y. Taroyan, Phys. Rev. Lett 101, 245001 (2008) it is claimed that a new MHD instability of the Alfven wave has been found: incompressible Alfven modes propagating in a compressible spatially varying flow were apparently exponentially amplified. We show that the results of the work follow from an impossible equilibrium and therefore should be disregarded.