Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An implementation of the microphysics in full general relativity :
  General relativistic neutrino leakage scheme   Performing fully general relativistic simulations taking account of
microphysical processes is one of long standing problems in numerical
relativity. One of main difficulties in implementation of weak interactions in
the general relativistic framework lies on the fact that the characteristic
timescale of weak interaction processes (the WP timescale) in hot dense matters
is much shorter than the dynamical timescale. Numerically this means that stiff
source terms appears in the equations so that an implicit scheme is in general
necessary to stably solve the relevant equations. Otherwise a very short
timestep will be required to solve them explicitly. Furthermore, in the
relativistic framework, the Lorentz factor is coupled with the rest mass
density and the energy density. The specific enthalpy is also coupled with the
momentum. Due to these couplings, it is very complicated to recover the
primitive variables and the Lorentz factor from conserved quantities. At the
current status, no implicit procedure have been proposed except for the case of
the spherical symmetry. Therefore, an approximate, explicit procedure is
developed in the fully general relativistic framework in this paper as an first
implementation of the microphysics toward a more realistic sophisticated model.
The procedure is based on the so-called neutrino leakage schemes which is based
on the property that the characteristic timescale in which neutrinos leak out
of the system (the leakage timescale) is much longer than the WP timescale. In
this paper, I present a detailed neutrino leakage scheme and a simple and
stable method for solving the equations explicitly in the fully general
relativistic framework. I also perform a test simulation to check the validity
of the present method, showing that it works fairly well.

26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat