Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A new general relativistic magnetohydrodynamics code for dynamical
  spacetimes   We present a new numerical code which solves the general relativistic
magneto-hydrodynamics (GRMHD) equations coupled to the Einstein equations for
the evolution of a dynamical spacetime within the conformally-flat
approximation. This code has been developed with the main objective of studying
astrophysical scenarios in which both, high magnetic fields and strong
gravitational fields appear, such as the magneto-rotational collapse of stellar
cores, the collapsar model of GRBs, and the evolution of neutron stars. The
code is based on an existing and thoroughly tested purely hydrodynamics code
and on its extension to accommodate weakly magnetized fluids (passive magnetic
field approximation). The numerical code we present here is based on
high-resolution shock-capturing schemes to solve the GRMHD equations together
with the flux constraint transport method to ensure the solenoidal condition of
the magnetic field. Since the astrophysical applications envisaged do not
deviate much from spherical symmetry, the conformal flatness condition
approximation is used for the formulation of the Einstein equations. In
addition, the code can handle several equations of state, from simple
analytical expressions to microphysical tabulated ones. In this paper we
present stringent tests of our new GRMHD numerical code, which show its ability
to handle all aspects appearing in the astrophysical scenarios for which the
code is intended, namely relativistic shocks, highly magnetized fluids, and
equilibrium configurations of magnetized neutron stars. As an application,
magneto-rotational core collapse simulations of a realistic progenitor are
presented, comparing the results with our previous finding in the passive
magnetic field approximation.

10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
21
The categories of this paper are: adap-org
31
The categories of this paper are: ao-sci