NADA-FLD: A General Relativistic, Multi-dimensional Neutrino-hydrodynamics Code Employing Flux-limited Diffusion. (arXiv:1901.10523v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Rahman_N/0/1/0/all/0/1">Ninoy Rahman</a> (1,2), <a href="http://arxiv.org/find/astro-ph/1/au:+Just_O/0/1/0/all/0/1">Oliver Just</a> (3), <a href="http://arxiv.org/find/astro-ph/1/au:+Janka_H/0/1/0/all/0/1">H.-Thomas Janka</a> (1) ((1) MPI f. Astrophysics, Garching, (2) Physik Department, TUM, (3) ABBL, RIKEN)
We present the new code NADA-FLD to solve multi-dimensional
neutrino-hydrodynamics in full general relativity (GR) in spherical polar
coordinates. The neutrino transport assumes the flux-limited diffusion (FLD)
approximation and evolves the neutrino energy densities measured in the frame
comoving with the fluid. Operator splitting is used to avoid multi-dimensional
coupling of grid cells in implicit integration steps involving matrix
inversions. Terms describing lateral diffusion and advection are integrated
explicitly with the Allen-Cheng method, which remains stable even in the
optically thin regime. We discuss several toy-model problems in one and two
dimensions to test the basic functionality and individual components of the
transport scheme. We also perform fully dynamic core-collapse supernova (CCSN)
simulations in spherical symmetry. For a Newtonian model we find good agreement
with the M1 code ALCAR, and for a GR model we reproduce the main effects of GR
in CCSNe already found by previous works.
We present the new code NADA-FLD to solve multi-dimensional
neutrino-hydrodynamics in full general relativity (GR) in spherical polar
coordinates. The neutrino transport assumes the flux-limited diffusion (FLD)
approximation and evolves the neutrino energy densities measured in the frame
comoving with the fluid. Operator splitting is used to avoid multi-dimensional
coupling of grid cells in implicit integration steps involving matrix
inversions. Terms describing lateral diffusion and advection are integrated
explicitly with the Allen-Cheng method, which remains stable even in the
optically thin regime. We discuss several toy-model problems in one and two
dimensions to test the basic functionality and individual components of the
transport scheme. We also perform fully dynamic core-collapse supernova (CCSN)
simulations in spherical symmetry. For a Newtonian model we find good agreement
with the M1 code ALCAR, and for a GR model we reproduce the main effects of GR
in CCSNe already found by previous works.
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