Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Energy Calculation of Magnetohydrodynamic Waves and Their Stability For
  Viscous Shearing Flows   A self-consistent, thermodynamic approach is employed to derive the wave
energy of a magnetohydrodynamic system within the harmonic approximation and to
obtain the familiar dispersion relation from the resulting equation of motion.
The evolution of the system due to an external perturbation is studied by a
linear response formalism, that also gives the energy absorbed by the
magnetohydrodynamic system from the external field. The calculated wave energy
reveals the presence of positive and negative energy waves, that coalesce
together to give rise to Kelvin - Helmholtz instability of the system. The
threshold value of this instability changes only slightly in the presence of a
small amount of viscosity, thus precluding the dissipative instability of the
negative energy waves. The prediction of such a dissipative instability by
earlier authors turns out to be the result of an erroneous choice of the
viscous drag force, that violates the fundamental law of Galilean invariance.

11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th