Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Global existence of weak solutions for quantum MHD equations   In this paper, we consider the quantum MHD equations with both the viscosity
coefficient and the magnetic diffusion coefficient are depend on the density.
we prove the global existence of weak solutions and perform the lower planck
limit in a 3-dimensional torus for large initial data. The global existence is
shown by using Faedo-Galerkin method and weak compactness techniques for the
adiabatic exponent $\gamma>1$.

18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
28
The categories of this paper are: alg-geom
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph