Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A New Algorithm for 2-D Transport for Astrophysical Simulations: I.
  General Formulation and Tests for the 1-D Spherical Case   We derive new equations using the mixed-frame approach for one- and
two-dimensional (axisymmetric) time-dependent radiation transport and the
associated couplings with matter. Our formulation is multi-group and
multi-angle and includes anisotropic scattering, frequency(energy)-dependent
scattering and absorption, complete velocity dependence to order v/c, rotation,
and energy redistribution due to inelastic scattering. Hence, the "2D"
realization is actually "6 1/2"-dimensional. The effects of radiation viscosity
are automatically incorporated. Moreover, we develop
Accelerated-Lambda-Iteration, Krylov subspace (GMRES),
Discontinuous-Finite-Element, and Feautrier numerical methods for solving the
equations and present the results of one-dimensional numerical tests of the new
formalism. The virtues of the mixed-frame approach include simple velocity
dependence with no velocity derivatives, straight characteristics, simple
physical interpretation, and clear generalization to higher dimensions. Our
treatment can be used for both photon and neutrino transport, but we focus on
neutrino transport and applications to core-collapse supernova theory in the
discussions and examples.

9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
25
The categories of this paper are: patt-sol
2
The categories of this paper are: math
16
The categories of this paper are: stat
20
The categories of this paper are: acc-phys
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg