Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: StaRMAP - A second order staggered grid method for spherical harmonics
  moment equations of radiative transfer   We present a simple method to solve spherical harmonics moment systems, such
as the the time-dependent $P_N$ and $SP_N$ equations, of radiative transfer.
The method, which works for arbitrary moment order $N$, makes use of the
specific coupling between the moments in the $P_N$ equations. This coupling
naturally induces staggered grids in space and time, which in turn give rise to
a canonical, second-order accurate finite difference scheme. While the scheme
does not possess TVD or realizability limiters, its simplicity allows for a
very efficient implementation in Matlab. We present several test cases, some of
which demonstrate that the code solves problems with ten million degrees of
freedom in space, angle, and time within a few seconds. The code for the
numerical scheme, called StaRMAP (Staggered grid Radiation Moment
Approximation), along with files for all presented test cases, can be
downloaded so that all results can be reproduced by the reader.

20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
31
The categories of this paper are: ao-sci
19
The categories of this paper are: eess
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
25
The categories of this paper are: patt-sol