Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Beyond Flux-Limited Diffusion: Parallel Algorithms for Multidimensional
  Radiation Hydrodynamics   This paper presents a new code for performing multidimensional radiation
hydrodynamic (RHD) simulations on parallel computers involving anisotropic
radiation fields and nonequilibrium effects. The radiation evolution modules
described here encapsulate the physics provided by the serial algorithm of
Stone et. al (ApJSupp, vol 80, pp. 819-845), but add new functionality with
regard to physics and numerics. Physics enhancments include the addition of
time dependence to the computation of the variable tensor Eddington factor
(VTEF) closure term, and a matter-radiation coupling scheme which is
particularly robust for nonequilibrium problems. Numerical highlights include a
discussion of how our code is implemented for parallel execution and a
description of our scalable linear solver module. We present a suite of
numerical tests from which the virtues and vices of our method may be gleaned;
these include nonequilibrium Marshak waves, 2-D "shadow" tests showing the
one-sided illumination of an opaque cloud, and full RHD+VTEF simulations of
radiating shocks. We conclude that radiation moment solutions closed with
variable tensor Eddington factors show a dramatic qualitative improvement over
results obtained with flux-limited diffusion, and further that this approach
has a bright future in the context of parallel RHD simulations in astrophysics.

27
The categories of this paper are: comp-gas
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
30
The categories of this paper are: q-alg
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
29
The categories of this paper are: funct-an