Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Divergence-Free Magnetohydrodynamics on Conformally Moving, Adaptive
  Meshes Using a Vector Potential Method   We present a new method for evolving the equations of magnetohydrodynamics
(both Newtonian and relativistic) that is capable of maintaining a
divergence-free magnetic field ($\nabla \cdot \mathbf{B} = 0$) on adaptively
refined, conformally moving meshes. The method relies on evolving the magnetic
vector potential and then using it to reconstruct the magnetic fields. The
advantage of this approach is that the vector potential is not subject to a
constraint equation in the same way the magnetic field is, and so can be
refined and moved in a straightforward way. We test this new method against a
wide array of problems from simple Alfven waves on a uniform grid to general
relativistic MHD simulations of black hole accretion on a nested,
spherical-polar grid. We find that the code produces accurate results and in
all cases maintains a divergence-free magnetic field to machine precision.

25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat