Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Generalized, energy-conserving numerical simulations of particles in
  general relativity. II. Test particles in electromagnetic fields and GRMHD   Direct observations of compact objects, in the form of radiation spectra,
gravitational waves from VIRGO/LIGO, and forthcoming direct imaging, are
currently one of the primary source of information on the physics of plasmas in
extreme astrophysical environments. The modeling of such physical phenomena
requires numerical methods that allow for the simulation of microscopic plasma
dynamics in presence of both strong gravity and electromagnetic fields. In
Bacchini et al. (2018) we presented a detailed study on numerical techniques
for the integration of free geodesic motion. Here we extend the study by
introducing electromagnetic forces in the simulation of charged particles in
curved spacetimes. We extend the Hamiltonian energy-conserving method presented
in Bacchini et al. (2018) to include the Lorentz force and we test its
performance compared to that of standard explicit Runge-Kutta and implicit
midpoint rule schemes against analytic solutions. Then, we show the application
of the numerical schemes to the integration of test particle trajectories in
general relativistic magnetohydrodynamic (GRMHD) simulations, by modifying the
algorithms to handle grid-based electromagnetic fields. We test this approach
by simulating ensembles of charged particles in a static GRMHD configuration
obtained with the Black Hole Accretion Code (BHAC).

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The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
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The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
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The categories of this paper are: plasm-ph
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The categories of this paper are: ao-sci
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The categories of this paper are: funct-an
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The categories of this paper are: econ
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The categories of this paper are: acc-phys
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an